Fix topBarHeight with UIModalPresentationPageSheet (#5749)

lib/ios/Constants.m

 }
 
 + (CGFloat)topBarHeight {
-	return [UIApplication.sharedApplication.delegate.window.rootViewController getTopBarHeight];
+	return [RCTPresentedViewController() getTopBarHeight];
 }
 
 + (CGFloat)statusBarHeight {

lib/ios/RNNStackController.m

 	return self.topViewController;
 }
 
-- (CGFloat)getTopBarHeight {
-	return self.navigationBar.frame.size.height;
-}
-
 - (UINavigationController *)navigationController {
 	return self;
 }

lib/ios/UINavigationController+RNNOptions.m

     lastViewControllerInStack.navigationItem.backBarButtonItem = backItem;
 }
 
+- (CGFloat)getTopBarHeight {
+    return self.navigationBar.frame.size.height;
+}
+
 @end