Merge "Smooth transition when switching dreaming." into tm-qpr-dev am: f932a297

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20041857



Change-Id: Idbbd394f57016b4609450819729f22ee102db478
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>