Merge "Ensure waitOnMainUntil runs on the main thread" into udc-qpr-dev am: 08497eca4a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24464970

Change-Id: I74232fd0b6b6c50dc3b7de3155fec5977ec20a6c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>