Remove unused styles (#22083)

Summary:
Removes unused styles.

NOTE: Lint rule `react-native/no-unused-styles` not added because of custom lint rule internally at Facebook that does this.
Pull Request resolved: https://github.com/facebook/react-native/pull/22083

Differential Revision: D12929443

Pulled By: TheSavior

fbshipit-source-id: d42b0be3db745e445447e65df3b78b61f53e4229

RNTester/js/PointerEventsExample.js

@@ -230,9 +230,6 @@ const styles = StyleSheet.create({
     borderColor: '#f0f0f0',
     backgroundColor: '#f9f9f9',
   },
-  bottomSpacer: {
-    marginBottom: 100,
-  },
 });
 
 exports.framework = 'React';