Merge "Delete hosttestlib as it's a legacy approach" am: 2f18dab43e am: 3ec8c61452 am: 4f5b4d7d57

Original change: https://android-review.googlesource.com/c/platform/development/+/1359842

Change-Id: Id2404058c1db4a8db6a3be2a19b92bb94b425d0a