Merge "Avoid lock screen flash when going to dream." into tm-qpr-dev am: cf4c1a62a6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20870275

Change-Id: If905937b58a52a9ed6b0579446be995cff43166f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>