update android build tools to 0.5.+

Android Gradle plug-in 0.5.0. This new version of the plug-in is not backwards compatible. When opening a project that uses an older version of the plug-in, Studio will show the following error as a balloon in the upper right corner of the IDE:

You will need to change the version of the Android Gradle plug-in to 0.5.0. Just click the link “Search in build.gradle files” to look for the places where this change needs to be made. (See the Troubleshooting section below for more info).