Move common compat lib to platform_testing am: 8660d2426a

Original change: https://android-review.googlesource.com/c/platform/test/suite_harness/+/1507720

Change-Id: I55f700d5a40c7c35ce6bc8c1616ff76f585e4e58
tree: e3b96ecf1fb5690fc7255b27f24e314e86cf7905
  1. common/
  2. OWNERS
  3. PREUPLOAD.cfg