Merge "Apply theme color and fade-in transition effect at the top of...

Merge "Apply theme color and fade-in transition effect at the top of One-handed mode" into sc-dev am: a08d1cb0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15234619

Change-Id: I544c9b53f7475690b4ff898e8455d893411d2c06