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/display/ScreenZoomSettings.java

@@ -71,9 +71,7 @@ public class ScreenZoomSettings extends PreviewSeekBarPreferenceFragment impleme
             mDefaultDensity = density.getDefaultDensity();
         }
 
-        if (usePreferenceScreenTitle()) {
-            getActivity().setTitle(R.string.screen_zoom_title);
-        }
+        getActivity().setTitle(R.string.screen_zoom_title);
     }
 
     @Override