Public animation library unit tests - add manifest and test activity am: cb2ba48d am: 1797fa30 am: 911d100e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/libs/systemui/+/22764153



Change-Id: I5c8a2cb0e8b906bb1603380e339f2283438093ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>