Merge "Polish entering pip from fullscreen with shell transition" into udc-dev...

Merge "Polish entering pip from fullscreen with shell transition" into udc-dev am: 16e51ba1 am: 116fb2d5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22952408



Change-Id: I5f69e21986244b87a51171a4fdeb54d79872fa0a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>