Back out "Enable Multiple Sheet Presentation in React Native" (facebook#46434)

Summary:
Pull Request resolved: facebook#46434

Original commit changeset: daa0cf95edb2

Original Phabricator Diff: D62202475

Changelog: [Internal]  revert previous modal presentation improvement

Reviewed By: sammy-SC

Differential Revision: D62474041

fbshipit-source-id: a4af6b5361dcc482e9bb3c2f45d614f9494f022e

Author: Mohamed Alsadek

packages/react-native/React/Views/RCTModalHostViewManager.m

@@ -64,9 +64,9 @@ - (void)presentModalHostView:(RCTModalHostView *)modalHostView
     if (self->_presentationBlock) {
       self->_presentationBlock([modalHostView reactViewController], viewController, animated, completionBlock);
     } else {
-      [[self _topMostViewControllerFrom:[modalHostView reactViewController]] presentViewController:viewController
-                                                                                          animated:animated
-                                                                                        completion:completionBlock];
+      [[modalHostView reactViewController] presentViewController:viewController
+                                                        animated:animated
+                                                      completion:completionBlock];
     }
   });
 }
@@ -107,26 +107,6 @@ - (void)invalidate
   _hostViews = nil;
 }
 
-#pragma mark - Private
-
-- (UIViewController *)_topMostViewControllerFrom:(UIViewController *)rootViewController
-{
-  UIViewController *topController = rootViewController;
-  while (topController.presentedViewController) {
-    topController = topController.presentedViewController;
-  }
-  if ([topController isKindOfClass:[UINavigationController class]]) {
-    UINavigationController *navigationController = (UINavigationController *)topController;
-    topController = navigationController.visibleViewController;
-    return [self _topMostViewControllerFrom:topController];
-  } else if ([topController isKindOfClass:[UITabBarController class]]) {
-    UITabBarController *tabBarController = (UITabBarController *)topController;
-    topController = tabBarController.selectedViewController;
-    return [self _topMostViewControllerFrom:topController];
-  }
-  return topController;
-}
-
 RCT_EXPORT_VIEW_PROPERTY(animationType, NSString)
 RCT_EXPORT_VIEW_PROPERTY(presentationStyle, UIModalPresentationStyle)
 RCT_EXPORT_VIEW_PROPERTY(transparent, BOOL)