[Regional Preferences] Remove u extension for subtitle of Language

- Remove the language tag info of subtitle in  Settings -> System -> Languages
 - Syuc same result to entry of numbering system.

Bug: b/268278327
Bug: b/268276472
Test: atest passed
Test: Manual test passed
Change-Id: I46dd0899059e9209b99f5ef3b7b84eb083d4e140

src/com/android/settings/localepicker/LocaleFeatureProviderImpl.java

@@ -27,10 +27,16 @@ public class LocaleFeatureProviderImpl implements LocaleFeatureProvider {
     @Override
     public String getLocaleNames() {
         final LocaleList locales = LocalePicker.getLocales();
+        Locale[] arrLocalesWithoutExtension = new Locale[locales.size()];
+        for (int i = 0; i < locales.size(); i++) {
+            arrLocalesWithoutExtension[i] = locales.get(i).stripExtensions();
+        }
         final Locale displayLocale = Locale.getDefault();
         return LocaleHelper.toSentenceCase(
                 LocaleHelper.getDisplayLocaleList(
-                        locales, displayLocale, 2 /* Show up to two locales from the list */),
+                        new LocaleList(arrLocalesWithoutExtension),
+                        displayLocale,
+                        2 /* Show up to two locales from the list */),
                 displayLocale);
     }
 }