title: Duplicate files copied in APK META-INF/LICENSE.txt. PackagingOptions doesnt helps
body: <p>Although I have read similar questions and tried to apply this code :</p>
  
  <pre><code>packagingOptions {
      exclude  'META-INF/LICENSE.txt'
  }
  </code></pre>
  
  <p>in my app build.gradle I still get the same error.</p>
  
  <p>The error message in logcat: </p>
  
  <pre><code>    Error:Execution failed for task ':kalturaClient:transformResourcesWithMergeJavaResForRelease'.
  &gt; com.android.build.api.transform.TransformException: com.android.builder.packaging.DuplicateFileException: Duplicate files copied in APK META-INF/LICENSE.txt
      File1: /home/teo/Documents/AndroidStudioWorkspace/Kaltura/DemoApplication/kalturaClient/libs/commons-codec-1.4.jar
      File2: /home/teo/Documents/AndroidStudioWorkspace/Kaltura/DemoApplication/kalturaClient/libs/commons-httpclient-3.1.jar
  </code></pre>
  
  <p>I have also tried to clean project but with no luck.
  I'm using Android Studio 1.5.1</p>
  
  <p>My build.gradle file is :</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
  compileSdkVersion 23
  buildToolsVersion "23.0.1"
  
  defaultConfig {
      applicationId "com.kaltura.activity"
      minSdkVersion 8
      targetSdkVersion 23
  }
  
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
      }
  }
  
  packagingOptions {
      exclude 'META-INF/LICENSE.txt'
  }
  
  }
  
  dependencies {
  compile project(':kalturaClient')
  compile 'com.android.support:support-v4:23.0.1'
  compile files('libs/WidevineDRM-Debug-5.0.0.12188.jar')
  compile files('libs/apksigtool.jar')
  compile files('libs/commons-codec-1.4.jar')
  compile files('libs/commons-httpclient-3.1.jar')
  compile files('libs/simple-social-sharing-1.0.0.jar')
  compile files('libs/universal-image-loader-1.2.1.jar')
  }
  </code></pre>