Merge "Make TransitionController's helper handle start and queue" into udc-dev am: d3cfcfdd am: a9ed4a5d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22583708



Change-Id: Ic1d1a4794ea59a4ce27e0625c1a7a33f234eb4c6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>