Show dialog when user chnages the region

1. show dialog
2. change the region of the top locale

Bug: 385047778
Flag: com.android.settings.flags.regional_preferences_api_enabled
Test: check hsv, atest
Change-Id: I9746cdec670899b3768dcd1e0aa59e1959dd7e06

src/com/android/settings/regionalpreferences/RegionPickerFragment.java

@@ -75,6 +75,8 @@ public class RegionPickerFragment extends DashboardFragment{
                 new SystemRegionAllListPreferenceController(
                     context, KEY_PREFERENCE_SYSTEM_REGION_LIST, parentLocaleInfo);
         final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        mSuggestedListPreferenceController.setFragment(this);
+        mSystemRegionAllListPreferenceController.setFragment(this);
         controllers.add(mSuggestedListPreferenceController);
         controllers.add(mSystemRegionAllListPreferenceController);
         return controllers;