Cleanup to ship ScrollViewStickyHeader experiment

Summary:
Changelog:
[General][Changed] Refactor ScrollViewStickyHeader to a functional component to remove unsafe lifecycles and mutations during render

Reviewed By: lunaleaps

Differential Revision: D28203776

fbshipit-source-id: 615c8e1cd9e9e26d25c7d02aee7e4a0bfc8ec6c3

Author: kacieb