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: 81769e64

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



Change-Id: I1cca9b4b4d3f9a1cf7c8c23bb4e332d9099d352e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>