title: ProGuard Configuration Parse Error, after enabling "minifyEnabled"
body: <p>My Android project is working completely fine, but when I enabled this option <strong><code>minifyEnabled true</code></strong> I got following error:</p>
  
  <pre><code>com.android.build.gradle.shrinker.parser.ProguardParserException: ProGuard configuration parser error:
      /Users/mss/.gradle/caches/transforms-1/files-1.1/play-services-base-11.8.0.aar/a9e603bf098b2c6866a5bdd73147cdc0/proguard.txt line 3:88 no viable alternative at input '&lt;fields&gt;'
  </code></pre>
  
  <p>This is the error I received every time I try to run my application with <strong><code>minifyEnabled true</code></strong>. Is there any solution to this problem.</p>
  
  <p>The dependencies I am using in my project are these:</p>
  
  <pre><code>dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
      implementation 'com.android.support:appcompat-v7:26.1.0'
      implementation 'com.android.support:design:26.1.0'
      implementation 'com.android.support.constraint:constraint-layout:1.0.2'
      implementation 'com.android.support:support-v4:26.1.0'
      implementation 'com.android.support:recyclerview-v7:26.1.0'
      implementation 'com.android.support:cardview-v7:26.1.0'
      implementation 'com.google.android.gms:play-services-auth:11.8.0'
  
      // Circle Image View
      implementation 'de.hdodenhof:circleimageview:2.2.0'
  
      // Firebase Dependencies
      implementation 'com.google.firebase:firebase-auth:11.8.0'
      implementation 'com.google.firebase:firebase-messaging:11.8.0'
      implementation 'com.google.firebase:firebase-crash:11.8.0'
  
      // Firebase UI Dependencies
      implementation 'com.firebaseui:firebase-ui-auth:3.1.0'
  
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'com.android.support.test:runner:1.0.1'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
  }
  </code></pre>
  
  <p>Moreover, configuration of <strong>app level build.gradle</strong> file are these:</p>
  
  <pre><code>buildTypes {
      release {
          debuggable false
       // minifyEnabled true
       // shrinkResources true
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  
      debug {
          debuggable true
       // minifyEnabled true
       // shrinkResources true
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  }
  </code></pre>
  
  <p>I'd commented two lines <strong>minifyEnabled true</strong> and <strong>shrinkResources true</strong> because these two are creating the problem.</p>