title: Android studio - Proguard seems to ignore rules, resulting in build error
body: <p>I keep getting the following errors while trying to make a signed apk using proguard:</p>
  
  <pre><code>Warning:com.dropbox.client2.DropboxAPI: can't find referenced class org.json.simple.JSONArray
  Warning:com.dropbox.client2.DropboxAPI$DropboxFileInfo: can't find referenced class org.json.simple.JSONValue
  Warning:com.dropbox.client2.DropboxAPI$Entry: can't find referenced class org.json.simple.JSONArray
  Warning:com.dropbox.client2.RESTUtility: can't find referenced class org.json.simple.parser.JSONParser
  Warning:com.dropbox.client2.RESTUtility: can't find referenced class org.json.simple.parser.ParseException
  Warning:com.dropbox.client2.jsonextract.JsonExtractionException: can't find referenced class org.json.simple.JSONValue
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.Picasso
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.Picasso$Builder
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.RequestCreator
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.Picasso
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.Picasso$Builder
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.RequestCreator
  Warning:com.inmobi.ads.aj: can't find referenced class com.squareup.picasso.Picasso
  </code></pre>
  
  <p>Even though i have <code>-keep public class com.dropbox.** { *; }</code>  in my proguard rules studio keeps hitting a wall about dropbox.Same thing happens with inmobi classes. Any suggestions? </p>
  
  <p>This is my proguard-rules file.</p>
  
  <pre><code># Add project specific ProGuard rules here.
  # By default, the flags in this file are appended to flags specified
  # in C:\Program Files (x86)\Android\android-sdk/tools/proguard/proguard-android.txt
  # You can edit the include path and order by changing the proguardFiles
  # directive in build.gradle.
  #
  # For more details, see
  #   http://developer.android.com/guide/developing/tools/proguard.html
  
  # Add any project specific keep options here:
  
  # If your project uses WebView with JS, uncomment the following
  # and specify the fully qualified class name to the JavaScript interface
  # class:
  #-keepclassmembers class fqcn.of.javascript.interface.for.webview {
  #   public *;
  #}
  
  -keep public class com.dropbox.** { *; } 
  
  
  # Appodeal
  -keep class com.appodeal.** { *; }
  -keep class org.nexage.** { *; }
  -keepattributes EnclosingMethod, InnerClasses, Signature, JavascriptInterface
  
  # Amazon
  -keep class com.amazon.** { *; }
  -dontwarn com.amazon.**
  
  # Mopub
  -keep public class com.mopub.**
  -keepclassmembers class com.mopub.** { public *; }
  -keep class * extends com.mopub.mobileads.CustomEventBanner {}
  -keep class * extends com.mopub.mobileads.CustomEventInterstitial {}
  -keep class * extends com.mopub.nativeads.CustomEventNative {}
  -keep class * extends com.mopub.mobileads.CustomEventRewardedVideo {}
  -dontwarn com.mopub.volley.toolbox.**
  
  # Applovin
  -keep class com.applovin.** { *; }
  -dontwarn com.applovin.**
  
  # Facebook
  -keep class com.facebook.ads.** { *; }
  
  -dontwarn com.avocarrot.**
  -keep class com.avocarrot.** { *; }
  -keepclassmembers class com.avocarrot.** { *; }
  -keep public class * extends android.view.View {
    public &lt;init&gt; (android.content.Context);
    public &lt;init&gt; (android.content.Context, android.util.AttributeSet);
    public &lt;init&gt; (android.content.Context, android.util.AttributeSet, int);
    public void set*(...);
  }
  
  -dontwarn android.support.v7.**
  -keep class android.support.v7.** { *; }
  -keep interface android.support.v7.** { *; }
  
  -keep public class com.google.android.gms.**
  -dontwarn com.google.android.gms.**
  
  -keep class butterknife.** { *; }
  -dontwarn butterknife.internal.**
  -keep class **$$ViewBinder { *; }
  
  -keepclasseswithmembernames class * {
      @butterknife.* &lt;fields&gt;;
  }
  
  -keepclasseswithmembernames class * {
      @butterknife.* &lt;methods&gt;;
  }
  
  
  # Appodeal
  -keep class com.appodeal.** { *; }
  -keep class org.nexage.** { *; }
  -keepattributes EnclosingMethod, InnerClasses, Signature, JavascriptInterface
  
  # Amazon
  -keep class com.amazon.** { *; }
  -dontwarn com.amazon.**
  
  # Mopub
  -keep public class com.mopub.**
  -keepclassmembers class com.mopub.** { public *; }
  -keep class * extends com.mopub.mobileads.CustomEventBanner {}
  -keep class * extends com.mopub.mobileads.CustomEventInterstitial {}
  -keep class * extends com.mopub.nativeads.CustomEventNative {}
  -keep class * extends com.mopub.mobileads.CustomEventRewardedVideo {}
  -dontwarn com.mopub.volley.toolbox.**
  
  # Applovin
  -keep class com.applovin.** { *; }
  -dontwarn com.applovin.**
  
  # Facebook
  -keep class com.facebook.ads.** { *; }
  -dontwarn com.facebook.ads.**
  
  # Chartboost
  -keep class com.chartboost.** { *; }
  -dontwarn com.chartboost.**
  
  # Unity Ads
  -keepattributes JavascriptInterface
  -keepattributes SourceFile,LineNumberTable
  -keep class com.unity3d.** { *; }
  
  # Yandex
  -keep class com.yandex.metrica.** { *; }
  -dontwarn com.yandex.metrica.**
  -keep class com.yandex.mobile.ads.** { *; }
  -dontwarn com.yandex.mobile.ads.**
  -keepattributes *Annotation*
  
  # StartApp
  -keep class com.startapp.** { *;}
  -dontwarn com.startapp.**
  -keepattributes Exceptions, InnerClasses, Signature, Deprecated, SourceFile, LineNumberTable, *Annotation*, EnclosingMethod
  
  # Flurry
  -keep class com.flurry.** { *; }
  -dontwarn com.flurry.**
  -keepattributes *Annotation*,EnclosingMethod,Signature
  -keepclasseswithmembers class * {
    public &lt;init&gt;(android.content.Context, android.util.AttributeSet, int);
  }
  
  # Avocarrot
  -keep class com.avocarrot.** { *; }
  -keepclassmembers class com.avocarrot.** { *; }
  -dontwarn com.avocarrot.**
  -keep public class * extends android.view.View {
    public &lt;init&gt;(android.content.Context);
    public &lt;init&gt;(android.content.Context, android.util.AttributeSet);
    public &lt;init&gt;(android.content.Context, android.util.AttributeSet, int);
    public void set*(...);
  }
  
  # Adcolony
  -keep class com.jirbo.adcolony.** { *;}
  -keep class com.immersion.** { *;}
  -dontnote com.immersion.**
  -dontwarn android.webkit.**
  -dontwarn com.jirbo.adcolony.**
  
  # Vungle
  -keep class com.vungle.** { public *; }
  -keep class javax.inject.*
  -keepattributes *Annotation*, Signature
  -keep class dagger.*
  -dontwarn com.vungle.**
  
  # MyTarget
  -keep class com.my.target.** { *; }
  -dontwarn com.my.target.**
  -keep class ru.mail.android.mytarget.** { *; }
  -dontwarn ru.mail.android.mytarget.**
  
  #Cheetah Mobile
  -keep class com.cmcm.** { *; }
  -dontwarn com.cmcm.**
  
  # Tapjoy
  -keep class com.tapjoy.** { *; }
  -dontwarn com.tapjoy.**
  
  # Revmob
  -keep class com.revmob.** { *; }
  -dontwarn com.revmob.**
  
  # Admob
  -keep class com.google.android.gms.ads.** { *; }
  
  # Google
  -keep class com.google.android.gms.common.GooglePlayServicesUtil {*;}
  -keep class com.google.android.gms.ads.identifier.** { *; }
  -dontwarn com.google.android.gms.**
  
  # Legacy
  -keep class org.apache.http.** { *; }
  -dontwarn org.apache.http.**
  -dontwarn android.net.http.**
  
  # Google Play Services library
  -keep class * extends java.util.ListResourceBundle {
      protected Object[][] getContents();
  }
  -keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
  }
  -keepnames class * implements android.os.Parcelable
  -keepclassmembers class * implements android.os.Parcelable {
    public static final *** CREATOR;
  }
  -keep @interface android.support.annotation.Keep
  -keep @android.support.annotation.Keep class *
  -keepclasseswithmembers class * {
    @android.support.annotation.Keep &lt;fields&gt;;
  }
  -keepclasseswithmembers class * {
    @android.support.annotation.Keep &lt;methods&gt;;
  }
  -keep @interface com.google.android.gms.common.annotation.KeepName
  -keepnames @com.google.android.gms.common.annotation.KeepName class *
  -keepclassmembernames class * {
    @com.google.android.gms.common.annotation.KeepName *;
  }
  -keep @interface com.google.android.gms.common.util.DynamiteApi
  -keep public @com.google.android.gms.common.util.DynamiteApi class * {
    public &lt;fields&gt;;
    public &lt;methods&gt;;
  }
  -keep class com.google.android.gms.common.GooglePlayServicesNotAvailableException {*;}
  -keep class com.google.android.gms.common.GooglePlayServicesRepairableException {*;} 
  
  # Google Play Services library 9.0.0 only
  -dontwarn android.security.NetworkSecurityPolicy
  -keep public @com.google.android.gms.common.util.DynamiteApi class * { *; }
  
  # support-v4
  -keep class android.support.v4.app.Fragment { *; }
  -keep class android.support.v4.app.FragmentActivity { *; }
  -keep class android.support.v4.app.FragmentManager { *; }
  -keep class android.support.v4.app.FragmentTransaction { *; }
  -keep class android.support.v4.content.LocalBroadcastManager { *; }
  -keep class android.support.v4.util.LruCache { *; }
  -keep class android.support.v4.view.PagerAdapter { *; }
  -keep class android.support.v4.view.ViewPager { *; }
  -keep class android.support.v4.content.ContextCompat { *; }
  
  # support-v7-recyclerview
  -keep class android.support.v7.widget.RecyclerView { *; }
  -keep class android.support.v7.widget.LinearLayoutManager { *; }
  
  
  -dontwarn okio.**
  -dontwarn okhttp3.**
  -dontwarn com.google.appengine.**
  -dontwarn javax.servlet.**
  
  # Support classes for compatibility with older API versions
  
  -dontwarn android.support.**
  -dontnote android.support.**
  
  
  
  -keep class org.** { *; }
  -keep class com.inmobi.ads.** { *; }
  
  
  -keep public class com.google.ads.** { public protected *; } 
  -keep public class com.inmobi.androidsdk.** { public protected *; }
  -keep public class com.millenialmedia.android.** { public protected *; }
  -keep public class com.mobclix.android.sdk.** { public protected *; }
  -keep public class com.jumptap.adtag.** { public protected *; }
  </code></pre>