Fix Hotspot & tethering settings crash

- Cannot omit addPreferencesFromResource even if UI is restricted

Bug: 287172382
Test: manual test
atest -c WifiTetherSettingsTest

Change-Id: I1f5c0215a635fddefe7eaa20c1d765634b505121

tests/robotests/src/com/android/settings/network/tether/TetherSettingsTest.java

@@ -131,10 +131,12 @@ public class TetherSettingsTest {
     @Test
     @Config(shadows = ShadowRestrictedSettingsFragment.class)
     public void onCreate_isUiRestricted_doNotSetupViewModel() {
+        doNothing().when(mTetherSettings).addPreferencesFromResource(anyInt());
         when(mTetherSettings.isUiRestricted()).thenReturn(true);
 
         mTetherSettings.onCreate(null);
 
+        verify(mTetherSettings).addPreferencesFromResource(anyInt());
         verify(mTetherSettings, never()).setupViewModel();
     }