Fix/rootview bounds iphone x (#3405)

* Fixed issue with rightButtons getting ignored in preference for empty Screen buttons

* Fixes an issue where on an iPhone X when showing the tab bar on pop from
a scrollable view to a non-scrollable view the root view's bounds
would be incorrect

ios/RCCViewController.m

 @property (nonatomic, strong) NSDictionary *originalNavBarImages;
 @property (nonatomic, strong) UIImageView *navBarHairlineImageView;
 @property (nonatomic, weak) id <UIGestureRecognizerDelegate> originalInteractivePopGestureDelegate;
+@property (nonatomic, strong) RCTRootView *rootView;
 @end
 
 @implementation RCCViewController
 }
 
 - (void)commonInit:(RCTRootView*)reactView navigatorStyle:(NSDictionary*)navigatorStyle props:(NSDictionary*)props {
-    self.view = reactView;
+    
+    self.rootView = reactView;
+    [self.view addSubview: reactView];
     
     self.edgesForExtendedLayout = UIRectEdgeNone; // default
     self.automaticallyAdjustsScrollViewInsets = NO; // default
     [self setStyleOnDisappear];
 }
 
+- (void)viewDidLayoutSubviews
+{
+    [super viewDidLayoutSubviews];
+    self.rootView.frame = self.view.bounds;
+}
+
 // most styles should be set here since when we pop a view controller that changed them
 // we want to reset the style to what we expect (so we need to reset on every willAppear)
 - (void)setStyleOnAppear {
                 UIViewController *viewController = (UIViewController*)obj;
                 [self addChildViewController:viewController];
                 viewController.view.frame = self.view.bounds;
-                [self.view addSubview:viewController.view];
+                [self.rootView addSubview:viewController.view];
                 [viewController didMoveToParentViewController:self];
             } else {
                 NSLog(@"addExternalVCIfNecessary: could not create instance. Make sure that your class is a UIViewController whihc confirms to RCCExternalViewControllerProtocol");