Apple TV support 1: existing Objective C code should compile for tvOS

Summary:
First commit for Apple TV support: changes to existing Objective-C code so that it will compile correctly for tvOS.
Closes https://github.com/facebook/react-native/pull/9649

Differential Revision: D3916021

Pulled By: javache

fbshipit-source-id: 34acc9daf3efff835ffe38c43ba5d4098a02c830

React/Views/RCTModalHostViewController.m

@@ -15,8 +15,10 @@
 @implementation RCTModalHostViewController
 {
   CGRect _lastViewFrame;
+#if !TARGET_OS_TV
   UIStatusBarStyle _preferredStatusBarStyle;
   BOOL _preferredStatusBarHidden;
+#endif
 }
 
 - (instancetype)init
@@ -25,8 +27,10 @@
     return nil;
   }
 
+#if !TARGET_OS_TV
   _preferredStatusBarStyle = [[UIApplication sharedApplication] statusBarStyle];
   _preferredStatusBarHidden = [[UIApplication sharedApplication] isStatusBarHidden];
+#endif
 
   return self;
 }
@@ -41,6 +45,7 @@
   }
 }
 
+#if !TARGET_OS_TV
 - (UIStatusBarStyle)preferredStatusBarStyle
 {
   return _preferredStatusBarStyle;
@@ -50,6 +55,7 @@
 {
   return _preferredStatusBarHidden;
 }
+#endif
 
 #if RCT_DEV
 - (UIInterfaceOrientationMask)supportedInterfaceOrientations