Merge "Delete hosttestlib as it's a legacy approach" am: 2f18dab43e am: 3ec8c61452 am: 4f5b4d7d57 am: 8d2f1078e8

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

Change-Id: Ic007a301c30a49066e6957c5cf18593c76258719