Show default app icon in default app screen.

- Renamed AdvancedAppSettings to DefaultAppSettings.
- Add logic to DefaultAppPreferenceController to also display icon.
- Modified DefautlAssistPrefController to suppress gear icon, and use
  the controller in default app setting UI to display icon.
- Remove dynamic injected payment setting activity and create the
  setting statically in xml.
- Add DefaultPaymentSettingsPreference to display default payment app
  title (no icon because we can't get it)

Change-Id: I6b8c768da0bafe5ec9a85ba9c79c7993b449be25
Fix: 36458534
Test: robotests

src/com/android/settings/applications/assist/ManageAssist.java

@@ -71,7 +71,8 @@ public class ManageAssist extends DashboardFragment {
     private static List<AbstractPreferenceController> buildPreferenceControllers(Context context,
             Lifecycle lifecycle) {
         final List<AbstractPreferenceController> controllers = new ArrayList<>();
-        controllers.add(new DefaultAssistPreferenceController(context));
+        controllers.add(new DefaultAssistPreferenceController(context, "default_assist",
+                true /* showSetting */));
         controllers.add(new AssistGesturePreferenceController(context, lifecycle, KEY_ASSIST,
                 true /* assistOnly */));
         controllers.add(new AssistContextPreferenceController(context, lifecycle));
@@ -81,7 +82,6 @@ public class ManageAssist extends DashboardFragment {
         return controllers;
     }
 
-
     public static final Indexable.SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider() {
                 @Override