[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

src/com/android/settings/network/NetworkProviderSettings.java

@@ -370,7 +370,6 @@ public class NetworkProviderSettings extends RestrictedSettingsFragment
                 }
             }
         };
-        registerForContextMenu(getListView());
         setHasOptionsMenu(true);
 
         if (savedInstanceState != null) {