Remove ChooserListAdapter notifyDataSetChange throttling

ChooserListAdapter notifyDataSetChange throttling period has been,
practically, reduced to 0 and this change removes the logic completely.
The remaining ChooserHandler's message turned into posting on the UI
thread and thus ChooserHandler is also removed.

Safety Check
All ChooserListAdapter#notifyDataSetChanged invocations I've found
(posted below) are originated by some posting on the main thread i.e.
not initiated from a view binding in the adapter.

Invocations
 - ChooserActivity.onHandlePackageChanged (and
 - ResolverActivity.onHandlePackageChanged)
 - ChooserListAdapter.onListRebuilt
 - ChooserListAdapter.updateAlphabeticalList
 - ChooserListAdapter.addServiceResults
 - ChooserListAdapter.completeServiceTargetLoading
 - ChooserListAdapter$<sorting task> from #createSortingTask
 - ChooserListAdapter.LoadDirectShareIconTask
 - ResolverListAdapter.LoadIconTask
 - ResolverListAdapter.LoadLabelTask

Fix: 257285237
Test: manual test
Test: atest IntentResolverUnitTests
Change-Id: I70eeababa2fa684f0a160ff6ed9ab0900e3c9648
3 files changed