Merge "Fix stalled background thread bug" into udc-dev am: b739e148 am: b2c86ab0 am: feb71c3f am: 7aa923d1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23765836



Change-Id: I9bd50822d4c3e5fb92fd591d7c3bf00bb0bccf6d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>