Remove the feature flag for using new title.

- remove all code that check for the feature flag, and use the new logic
by default.

Change-Id: I7fbe60da84c1c0f35e7241402a71d2bc4cd300e6
Fixes: 64564191
Test: make RunSettingsRoboTests

src/com/android/settings/widget/RadioButtonPickerFragment.java

@@ -68,9 +68,6 @@ public abstract class RadioButtonPickerFragment extends InstrumentedPreferenceFr
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         super.onCreatePreferences(savedInstanceState, rootKey);
-        if (!usePreferenceScreenTitle()) {
-            addPreferencesFromResource(R.xml.placeholder_prefs);
-        }
         updateCandidates();
     }