fix: resolve Require Cycle warning (#27851)

Summary:
When I was testing React Native 0.62-rc.1, I noticed that console was showing a warning for Require Cycle as shown in image below

![Screen Shot 2020-01-24 at 12 22 38](https://user-images.githubusercontent.com/6936373/73042467-998dff00-3ea4-11ea-911c-955d55fd0743.png)

This is because ScrollResponder was importing `ScrollView` to get the `typeof ScrollView`.
I've made an export for ScrollView type in `ScrollView` so that Require cycle warning will not show up.

## Changelog

[General] [Fixed] - Remove Require cycle warning.
Pull Request resolved: #27851

Differential Revision: D19577644

Pulled By: cpojer

fbshipit-source-id: 257b9421a91244d69394375102cfbe683326bba2

Author: Naturalclar

Libraries/Components/ScrollResponder.js

@@ -18,13 +18,13 @@ const ReactNative = require('../Renderer/shims/ReactNative');
 const TextInputState = require('./TextInput/TextInputState');
 const UIManager = require('../ReactNative/UIManager');
 const Platform = require('../Utilities/Platform');
-const ScrollView = require('./ScrollView/ScrollView');
 import Commands from './ScrollView/ScrollViewCommands';
 
 const invariant = require('invariant');
 const performanceNow = require('fbjs/lib/performanceNow');
 
 import type {PressEvent, ScrollEvent} from '../Types/CoreEventTypes';
+import typeof ScrollView from './ScrollView/ScrollView';
 import type {Props as ScrollViewProps} from './ScrollView/ScrollView';
 import type {KeyboardEvent} from './Keyboard/Keyboard';
 import type EmitterSubscription from '../vendor/emitter/EmitterSubscription';
@@ -468,7 +468,7 @@ const ScrollResponderMixin = {
       ({x, y, animated} = x || {});
     }
 
-    const that: React.ElementRef<typeof ScrollView> = (this: any);
+    const that: React.ElementRef<ScrollView> = (this: any);
     invariant(
       that.getNativeScrollRef != null,
       'Expected scrollTo to be called on a scrollViewRef. If this exception occurs it is likely a bug in React Native',
@@ -492,7 +492,7 @@ const ScrollResponderMixin = {
     // Default to true
     const animated = (options && options.animated) !== false;
 
-    const that: React.ElementRef<typeof ScrollView> = (this: any);
+    const that: React.ElementRef<ScrollView> = (this: any);
     invariant(
       that.getNativeScrollRef != null,
       'Expected scrollToEnd to be called on a scrollViewRef. If this exception occurs it is likely a bug in React Native',
@@ -531,7 +531,7 @@ const ScrollResponderMixin = {
       );
     }
 
-    const that: React.ElementRef<typeof ScrollView> = this;
+    const that: React.ElementRef<ScrollView> = this;
     invariant(
       that.getNativeScrollRef != null,
       'Expected zoomToRect to be called on a scrollViewRef. If this exception occurs it is likely a bug in React Native',
@@ -547,7 +547,7 @@ const ScrollResponderMixin = {
    * Displays the scroll indicators momentarily.
    */
   scrollResponderFlashScrollIndicators: function() {
-    const that: React.ElementRef<typeof ScrollView> = (this: any);
+    const that: React.ElementRef<ScrollView> = (this: any);
     invariant(
       that.getNativeScrollRef != null,
       'Expected flashScrollIndicators to be called on a scrollViewRef. If this exception occurs it is likely a bug in React Native',