[iOS] Remove private symbols in Expo Go

RCTKeyCommands uses iOS private symbols to hook keyboard commands.
originally it's debug build only, however, we enable `RCT_DEV` in Expo Go even on release build.
this change updates the functionalities for simulator build only
which aligns to expo/expo#14735.

Author: Kudo

React/Base/RCTKeyCommands.m

@@ -14,7 +14,7 @@
 #import "RCTDefines.h"
 #import "RCTUtils.h"
 
-#if RCT_DEV
+#if TARGET_IPHONE_SIMULATOR
 
 @interface UIEvent (UIPhysicalKeyboardEvent)