[Android] Add support for specifying android version codes

Add support for specifying android version codes, which is necessary for publishing multiple apk to google play. Follows the recommendation for including ABI in version code from  http://software.intel.com/en-us/blogs/2012/11/12/how-to-publish-your-apps-on-google-play-for-x86-based-android-devices-using. The schemes ensures that all x86 version codes are higher than arm version codes so google play will never install an arm version on an x86 device if there also is an x86 apk in the store.
    
Added some tests to make_apk_test and published x86 and arm crosswalk apk to google play.
Use --app-versionCodeBase=n and --arch=x86 or --arch=arm to use this feature and it will set version code that includes ABI, which enables multiple apk's

You can also specify the full version code yourself
 --app-versionCode=n

Before this change, script was setting versionName, but not versionCode so it was not possible to update an APK in the store or publish multiple APK's