We need to retain the main Looper between tests because app code might hold onto it in a static field.
We also need to softly refer to it to avoid permgen overuse.
Merge branch 'xian/fix-looper'

* xian/fix-looper:
  We need to retain the main Looper between tests because app code might hold onto it in a static field. We also need to softly refer to it to avoid permgen overuse.