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/language/PhoneLanguagePreferenceController.java

@@ -68,8 +68,7 @@ public class PhoneLanguagePreferenceController extends AbstractPreferenceControl
 
     @Override
     public boolean handlePreferenceTreeClick(Preference preference) {
-        if (!InstrumentedPreferenceFragment.usePreferenceScreenTitle()
-                || !KEY_PHONE_LANGUAGE.equals(preference.getKey())) {
+        if (!KEY_PHONE_LANGUAGE.equals(preference.getKey())) {
             return false;
         }
         Utils.startWithFragment(mContext, LocaleListEditor.class.getName(), null, null, 0,