Merge "Hide taskbar background when notification shade is expanded" into sc-v2-dev am: add188f339 am: d6123537c5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16102657

Change-Id: I68306fb21825ab94cd8aa46b35ffb0e49bc5a6ac