Merge "Inject back key events if no focus window found." into tm-qpr-dev am:...

Merge "Inject back key events if no focus window found." into tm-qpr-dev am: 117bab59 am: 23c3dd02

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19144840



Change-Id: I678242b3a7b6164c6782b82040d386417971f8dc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>