Merge "Cancel the back animation if the topCallback is removed or the WindowOnBackInvokedDispatcher is detached from the window." into udc-dev am: b3805c73 am: 530f0cd1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23516257



Change-Id: Id50432f714e8e57bc09a5c23a91e0286985a4cab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>