Merge "Dispatch KEYCODE_BACK to the full input pipeline in compat callback."...

Merge "Dispatch KEYCODE_BACK to the full input pipeline in compat callback." into tm-dev am: d47a1729 am: 2830b6c6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17411191



Change-Id: I58561754e1edfdc4da706b4e4dd48407998647b7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>