Summary:
This is dead code. Let's remove this for now.
This api is unsafe: if it's called from a non-ui thread, it may dispatch to the ui thread synchronously.
Changelog: [iOS][Removed] - Remove RCTFloorPixelValue
Reviewed By: NickGerleman
Differential Revision: D72260694
fbshipit-source-id: d032917643c957a395ee380ef925a047abd5dace