Merge "Remove Activity if it enters PiP without window" into rvc-dev am: 81224e6f76 am: d6a9b8078a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21564420

Change-Id: I208a16f400a8e34c28fb9d9805c1cf6646e6d973
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>