Retry: Specify test dependecies in rules.gradle

Now that tests are using Robolectric 3, it should not break the internal
build.

This also updates the android gradle plugin. The block is wrapped in an
if statement, in case someone using plugin version 1.0 includes
rules.gradle.

Change-Id: Ib054e2d39cf1e3bc0746740659f4e5449b2e1375
2 files changed