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: c0b63d30 am: 872aa888

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



Change-Id: If919d44eb27520a51ca75872e49024b0a28ccdab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>