Android : Ensure assets are populated _before_ packaging theme into aar.

android/build.gradle

@@ -22,7 +22,7 @@ buildscript {
     }
 }
 
-apply plugin: 'com.android.library'
+apply plugin: 'android-library'
 
 android {
     compileSdkVersion 21
@@ -131,6 +131,8 @@ android {
         compileTask -> compileTask.dependsOn jniBuild
     }
 
+    assemble.dependsOn unzipDeps
+
     task cleanNative(type: Exec) {
         commandLine getNdkBuildCmd(), 'clean'
     }