Merge "Use dispatching for forgetCancellationSignal" into udc-qpr-dev am: 41772b9c am: 9579c4f5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24830891



Change-Id: I233dc739971eacd0820a4b60274eed97297e8f69
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>