Public animation library unit tests - add manifest and test activity am: cb2ba48d am: 05b07bd5 am: 51214b14

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



Change-Id: Iefc8ca556d3f7f19282ed295ae5755e67590a31a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>