New Keyboard Avoiding Component Use Cases (#29857)

Summary:
* New use cases for keyboard avoiding component in rn-tester

## Changelog
[General] [Changed] - Changed use cases for keyboard avoiding component in rn-tester

## Test Plan
* Tested app in both Android and iOS

After -
![image](https://user-images.githubusercontent.com/42653703/92625233-07792080-f2e6-11ea-8e97-e606b8a2a1ec.png)
Before -
![image](https://user-images.githubusercontent.com/42653703/92625250-0d6f0180-f2e6-11ea-99db-e833c01b7b5c.png)

Pull Request resolved: https://github.com/facebook/react-native/pull/29857

Reviewed By: cpojer

Differential Revision: D23643563

Pulled By: rickhanlonii

fbshipit-source-id: ba4850670e1c4ba0b167b7437dc2bd0c4a6dd60b