Fix SwitchPreference in UserRestriction page

Change-Id: Id4357327dbc98c2b84dc2550f423c31a5b04b75a
Fix: 30300659

Author: tony-mak

app/src/main/java/com/afwsamples/testdpc/policy/UserRestrictionsDisplayFragment.java

@@ -192,11 +192,11 @@ public void onCreate(Bundle savedInstanceState) {
     @Override
     public void onCreatePreferences(Bundle bundle, String rootkey) {
         PreferenceScreen preferenceScreen = getPreferenceManager().createPreferenceScreen(
-                getActivity());
+                getPreferenceManager().getContext());
         setPreferenceScreen(preferenceScreen);
 
         for (UserRestriction restriction : ALL_USER_RESTRICTIONS) {
-            SwitchPreference preference = new SwitchPreference(getActivity());
+            SwitchPreference preference = new SwitchPreference(getPreferenceManager().getContext());
             preference.setTitle(restriction.titleResId);
             preference.setKey(restriction.key);
             preference.setOnPreferenceChangeListener(this);