Merge "Cancel the back animation if the topCallback is removed or the...

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>