[Regional Preference] Remove unit tes tof systemproperty

- Unit test of System Property failed due to timing issue. Remove it to avoid to impact formal unit test tracker.

 - This system property is feature flag.

Bug: b/265410669
Test: atest passed.
Change-Id: I65b4a34e1a362428ccb18611c90702650a5cdf8f

src/com/android/settings/regionalpreferences/RegionalPreferencesController.java

@@ -42,7 +42,7 @@ public class RegionalPreferencesController  extends BasePreferenceController {
      */
     @Override
     public int getAvailabilityStatus() {
-        return SystemProperties.getBoolean(FEATURE_PROPERTY, false)
+        return SystemProperties.getBoolean(FEATURE_PROPERTY, true)
                 ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
     }
 }