Summary:
Sets up an experiment that enables `collapsable` in Fabric for iOS. This will enable us to validate with production data that enabling the use of this prop does not cause unexpected regressions.
Changelog:
[internal]
Reviewed By: mdvacca
Differential Revision: D27987619
fbshipit-source-id: 9b1c0ff45bed09b1e72ad7d9c782f07bb4211cc6