Sharesheet - Make UI more responsive to touches when loading

ListView will try to prevent errant touches while data is being
loaded. With Sharesheet, this can happen quite frequently so 1:
eliminate unnecessary notifyDataSetChanged calls and 2: batch up the
remaining calls and release a single call on an interval.

Bug: 126568576
Test: atest ChooserActivityTest && atest ResolverActivityTest
Change-Id: I3207f207910a0c9223a1b562243d9db612f93b0a