[GAR] Remove the registerForContextMenu for getting the correct TalkBack

feedback

[Root Cause]
Call the registerForContextMenu to set the view to long-clickable, so
the TalkBack will feedback the "List, Double-tap and hold to long press"

Bug: 187438189
Test: manual test
      make RunSettingsRoboTests ROBOTEST_FILTER=NetworkProviderSettingsTest
Change-Id: I5c33d400a405062e51caccda7a9abe9e76aafea7