Delegate PrintServicesLoader to the framework's one

1. Remove the duplicated PrintServicesLoader in Settings
2. Make a androidx.loader in Settings and internally just delegate all calls to the real PrintServicesLoader
3. Get the result from the real loader

Test: manual
Fixes: 111581651
Change-Id: I2a9b3653f5c68f8383a468cd16ef5f7c3fd4bc3a

src/com/android/settings/print/PrintServiceSettingsFragment.java

@@ -286,7 +286,7 @@ public class PrintServiceSettingsFragment extends SettingsPreferenceFragment
 
     @Override
     public Loader<List<PrintServiceInfo>> onCreateLoader(int id, Bundle args) {
-        return new PrintServicesLoader(
+        return new SettingsPrintServicesLoader(
                 (PrintManager) getContext().getSystemService(Context.PRINT_SERVICE), getContext(),
                 PrintManager.ALL_SERVICES);
     }