Add WifiWatchdogService toggle to Wifi Settings

Toggle is located in Settings->Wifi Settings->Advanced Wifi Settings

Change-Id: I0f8f2b6353842dae0b47dca1dd48994e42505169

src/com/android/settings/wifi/AdvancedWifiSettings.java

@@ -76,6 +76,7 @@ public class AdvancedWifiSettings extends SettingsPreferenceFragment
         }
     }
 
+    @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
         String key = preference.getKey();
         if (key == null) return true;