Summary:
Sets up an injection mechanism for experimenting in production with an alternate implementation of `createAnimatedComponent`.
This will be used to implement and refine a new `createAnimatedComponent` that is compatible with concurrent rendering.
Changelog:
[Internal]
Reviewed By: lunaleaps
Differential Revision: D28799739
fbshipit-source-id: 46ba2dd6137f7bf73ce8a659698533ed3985516f
Tim Yung