Merge "Move SharedPreferences code to its own class." into tm-qpr-dev am: 3233010c5a

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/20446860

Change-Id: I397957b5d9584aebf4182930763a2c5ab6401073
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>