Rename duplicate name `<ScrollView>` example on RNTester (#28515)

Summary:
Tiny change. When searching for `scro` in the RNTester, two `<ScrollView>`s come up, from different example files. One is the "simple" one and the other is the "regular" one.

Before:
<img width="370" alt="Screen Shot 2020-04-03 at 17 14 01" src="https://user-images.githubusercontent.com/100233/78377338-c6ab0c00-75cf-11ea-9c45-2dcdd6460f6d.png">

After:
<img width="369" alt="Screen Shot 2020-04-03 at 17 13 38" src="https://user-images.githubusercontent.com/100233/78377371-cf034700-75cf-11ea-89ea-aa3ff2f3988c.png">

## Changelog

[Internal] [Changed] - Rename the "simple" ScrollView example in RNTester to "ScrollSimpleView".
Pull Request resolved: https://github.com/facebook/react-native/pull/28515

Test Plan: - Try to search for `scro` in RNTester.

Reviewed By: fkgozali

Differential Revision: D20842264

Pulled By: hramos

fbshipit-source-id: 3db54a826ae774108e62690e7f154e85b541520f

RNTester/js/examples/ScrollView/ScrollViewSimpleExample.js

@@ -91,7 +91,7 @@ const styles = StyleSheet.create({
   },
 });
 
-exports.title = '<ScrollView>';
+exports.title = '<ScrollSimpleView>';
 exports.description =
   'Component that enables scrolling through child components.';