title: gradle error when Theme declare-styleable in two libraries
body: <p>I tried to compile an android project using the following build.gradle file:</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:0.6.+'
      }
  }
  apply plugin: 'android'
  
  repositories {
      maven {
          url 'https://github.com/Goddchen/mvn-repo/raw/master/'
      }
      mavenCentral()
  }
  
  android {
      compileSdkVersion 18
      buildToolsVersion "18.1.1"
  
      defaultConfig {
          minSdkVersion 8
          targetSdkVersion 18
      }
  }
  
  dependencies {
          compile 'com.android.support:appcompat-v7:18.0.+'
          compile 'com.android.support:support-v4:18.0.+'
  
          compile 'com.google.android.gms:play-services:3.2.+'
  
          compile 'com.facebook.android:facebook:3.5.+'
          compile 'com.android:volley:1.0'
          compile 'org.jraf:android-switch-backport:1.0'
  
  }
  </code></pre>
  
  <p>But this fails with the following error:</p>
  
  <pre><code>:TestProject:processDebugResources
  /home/lukas/apps/Splots_test/apps/TestProject/build/res/all/debug/values/values.xml:1622: error: Error: No resource found that matches the given name: attr 'switchStyle'.
  :TestProject:processDebugResources FAILED
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':TestProject:processDebugResources'.
  &gt; Could not call IncrementalTask.taskAction() on task ':TestProject:processDebugResources'
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  BUILD FAILED
  </code></pre>
  
  <p>After looking at the generated values.xml I found that it was missing the declare-styleable "Theme" section of android-switch-backport.</p>
  
  <p>This section is defined in both Appcompat and AndroidSwitchBackport, but only one of these is included in the final file:</p>
  
  <pre><code>lukas@lukas-Workstation:~/apps/Splots_test/apps$ grep -r 'declare-styleable name="Theme"' .
  ./TestProject/build/exploded-bundles/ComAndroidSupportAppcompatV71800.aar/res/values/values.xml:    &lt;declare-styleable name="Theme"&gt;
  ./TestProject/build/exploded-bundles/OrgJrafAndroidSwitchBackport10.aar/res/values/values.xml:    &lt;declare-styleable name="Theme"&gt;
  </code></pre>
  
  <p>Is there any way to tell gradle it should merge the attributes of both libraries?</p>