Merge "Improve enter and dismiss transition by using snapshot" into udc-dev...

Merge "Improve enter and dismiss transition by using snapshot" into udc-dev am: 472c42cc am: 7397b8f1

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



Change-Id: If17211286b1016d19cacf6b9c70f426085bc84d0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>