Fix talkback will speak "disabled" when select empty preference

Set empty preference as not selectable to make talkback
not to detect it.

Bug: 178068585
Bug: 178067426
Test: manually test
Change-Id: Id293a61494cd0bdd79d104918502101cb5caf050

src/com/android/settings/bluetooth/BluetoothDetailsProfilesController.java

@@ -297,6 +297,7 @@ public class BluetoothDetailsProfilesController extends BluetoothDetailsControll
             preference.setEnabled(false);
             preference.setKey(KEY_BOTTOM_PREFERENCE);
             preference.setOrder(ORDINAL);
+            preference.setSelectable(false);
             mProfilesContainer.addPreference(preference);
         }
     }