Merge "Cancel the back animation if the topCallback is removed or the WindowOnBackInvokedDispatcher is detached from the window." into udc-dev am: b3805c73 am: 1d2cbf45

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



Change-Id: I9423ae72a219c3fdef1251a24927ee249dd4c194
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>