title: Android Generate Signed APK getting duplicate issue
body: <p>When I try to generate Signed APK, I am getting the following error</p>
  
  <p>Error:Execution failed for task ':app:transformClassesWithJarMergingForRelease'. > com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: com/google/gson/annotations/Expose.class</p>
  
  <p>The Debug APK is working perfectly. After I include Facebook SDK then only I am facing this issue... Can anyone help me how to solve this issue    </p>
  
  <pre><code>buildscript {
  repositories {
      maven { url 'https://maven.fabric.io/public' }
  }
  
  dependencies {
      classpath 'io.fabric.tools:gradle:1.21.5'
  }
  }
  apply plugin: 'com.android.application'
  apply plugin: 'io.fabric'
  
  repositories {
   maven { url 'https://maven.fabric.io/public' }
  }
  
  
  android {
  compileSdkVersion 25
  buildToolsVersion "25.0.2"
  defaultConfig {
      applicationId "mani.com.howhighru"
      minSdkVersion 15
      targetSdkVersion 25
      versionCode 1
      versionName "1.0"
      testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      multiDexEnabled true
  }
  
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  }
  dexOptions {
      javaMaxHeapSize "4g"
  }
  }
  
  dependencies {
  compile fileTree(dir: 'libs', include: ['*.jar'])
  compile 'com.android.support:multidex:1.0.1'
  compile 'com.google.android.gms:play-services:10.2.0'
  compile 'com.googlecode.json-simple:json-simple:1.1'
  compile 'com.facebook.android:facebook-android-sdk:[4,5)'
  testCompile 'junit:junit:4.12'
  compile('com.twitter.sdk.android:twitter:2.3.1@aar') {
      transitive = true;
  }
  }
  </code></pre>