Change React Native application layout check

Reviewed By: shergin

Differential Revision: D7076910

fbshipit-source-id: dc6df2dee886bbdf139d6e50192d621efad6d57e

React/Modules/RCTI18nUtil.m

@@ -5,10 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import <Foundation/Foundation.h>
-
 #import "RCTI18nUtil.h"
 
+#import <UIKit/UIKit.h>
+
 @implementation RCTI18nUtil
 
 + (instancetype)sharedInstance
@@ -98,9 +98,8 @@
 // Check if the current application language is RTL
 - (BOOL)isApplicationPreferredLanguageRTL
 {
-  NSString *preferredAppLanguage = [[[NSBundle mainBundle] preferredLocalizations] objectAtIndex:0];
-  NSLocaleLanguageDirection direction = [NSLocale characterDirectionForLanguage:preferredAppLanguage];
-  return direction == NSLocaleLanguageDirectionRightToLeft;
+  NSWritingDirection direction = [NSParagraphStyle defaultWritingDirectionForLanguage:nil];
+  return direction == NSWritingDirectionRightToLeft;
 }
 
 @end