Merge "Preventing from double remove starting window after Activity destoryed" into udc-dev am: b9df9a61b9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23657536

Change-Id: Ia49a5bbf8c8cb13c13143996ecd0e21c40e83eef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>