Summary:
We shouldn't be accessing `nativeFabricUIManager` directly because it's untyped and makes it harder to mock the values.
This migrates all existing usages to the `FabricUIManager` module.
In the long term, we should refactor this global binding as a TurboModule.
Changelog: [internal]
Reviewed By: yungsters
Differential Revision: D44029301
fbshipit-source-id: d8300acb5dabe4ba27c7f0242230e203c0e8c674