Merge "Improve enter and dismiss transition by using snapshot" into udc-dev am: 472c42cc am: 3cdc9439

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23258461



Change-Id: I406ab39b0f403929a4c58fee5322a351cad8fc40
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>