Merge "Fix stalled background thread bug" into udc-qpr-dev am: 7b161731

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23814735



Change-Id: I57a7d8494aa857947b93b95496f134b370bcf51a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>