Deprecate AppListPreference and AppListPrefWithSettings

- Convert ManageAssist into DashboardFragment
- Convert default assist pref to DefaultAppPickerFragment
- Add PreferenceController for each pref
- Add tests

Bug: 35203386
Test: make RunSettingsRoboTests

Change-Id: I0350a06cae7457809fb261e2d8ec99eda80cc50a

src/com/android/settings/applications/defaultapps/DefaultSmsPreferenceController.java

@@ -47,7 +47,7 @@ public class DefaultSmsPreferenceController extends DefaultAppPreferenceControll
     protected DefaultAppInfo getDefaultAppInfo() {
         final ComponentName app = SmsApplication.getDefaultSmsApplication(mContext, true);
         if (app != null) {
-            return new DefaultAppInfo(mUserId, app, null /* summary */);
+            return new DefaultAppInfo(mUserId, app);
         }
         return null;
     }