Restoring pinned shortcuts to original state after restore

Creating an no-op backup agent in settings. This ensures that
we get onRestoreFinished callback after restore is finished where we
can update all pinned shortcuts.

Bug: 110016648
Test: Verified backup->clear-data->restore path on device
Change-Id: Id14d0792d60ba08d97078a31a81d2b63ab8ce109