Fix screenshot test failures for E2E tests in ScrollViewExamples

Summary:
Adding a minHeight property messed up some screenshot tests. T93437971

I'm honestly not sure why this happened since that ScrollView container has a fixed height set of 300, so it shouldn't have changed heights... It didn't change heights in RNTester.

We should probably take the full example (including title etc.) from RNTester for our E2E tests to avoid these types of weird layout breakages in the future.

Changelog: [Internal]

Reviewed By: lunaleaps

Differential Revision: D29201224

fbshipit-source-id: 30b98fa43d06eec1da345becc473690a3b075fb7

packages/rn-tester/js/examples/ScrollView/ScrollViewExample.js

@@ -1273,13 +1273,11 @@ const styles = StyleSheet.create({
     backgroundColor: 'rgba(100,215,255,.3)',
   },
   button: {
-    flex: 1,
     margin: 5,
     padding: 5,
     alignItems: 'center',
     backgroundColor: '#cccccc',
     borderRadius: 3,
-    minHeight: 30,
   },
   row: {
     flexDirection: 'row',