Merge "Give each preference screen its own activity and toolbar title" into sc-dev am: 8d6ca68786 am: a9a063294e am: b6711ae334

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14709732

Change-Id: I5a6f54696063f7c9b042f2c40303d23eb66f2c42