[DataStore] Migrate LocaleNotification SharedPreferences to BackupRestoreStorage

Bug: 325144964
Test: Manual tests
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:cc0a94d73247fa81eff0054a0dcf06e99c45adb1)
Merged-In: I195ee91f29030fcfe7176ed0c18fb2e2d0d40257
Change-Id: I195ee91f29030fcfe7176ed0c18fb2e2d0d40257
3 files changed