Merge "Fixed the issue that the MainSwitchPreference is invalid after the page is resumed." into tm-dev

packages/SettingsLib/MainSwitchPreference/src/com/android/settingslib/widget/MainSwitchPreference.java

@@ -144,6 +144,5 @@ public class MainSwitchPreference extends TwoStatePreference implements OnMainSw
         for (OnMainSwitchChangeListener listener : mSwitchChangeListeners) {
             mMainSwitchBar.addOnSwitchChangeListener(listener);
         }
-        mSwitchChangeListeners.clear();
     }
 }