Merge "Update taskbar background color to match overview's dark mode" into sc-v2-dev am: 5ba08b348b am: e0da81dd34

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15388923

Change-Id: Ie0bd1d7514f242fd3bcee422cf27af3a283a74ea