Merge "[pm] shell command to wait for handler(s)" into udc-dev am: 5d67812f am: 721f4af1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23139396



Change-Id: I034bb098e1829df6180ea32bc956e39347004dd4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>