Merge "Fix NPE by making Toast on UI thread" into udc-dev am: 8b0a18473b am: 71a32fafcc

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21803381

Change-Id: Id978dca0259c76e2153bcbce7e3ccdcbf3f89eba
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>