refactor(rn tester app): change dimensions example to hooks (#35084)

Summary:
This pull request migrates the dimensions example to using React Hooks.

## Changelog
[General] [Changed] - RNTester: Migrate Dimensions to hooks

Pull Request resolved: https://github.com/facebook/react-native/pull/35084

Test Plan: The animation works exactly as it did as when it was a class component

Reviewed By: yungsters

Differential Revision: D40779014

Pulled By: NickGerleman

fbshipit-source-id: e740684d3022a945da5abc33b2e8834c6cfabb97