Summary:
Changelog: [Internal]
Problem:
The Bridge holds and exposes the bundle URL for native modules to inspect via `bridge.bundleURL`.
Solution:
This follows the same pattern we've been using for attaching objects to native modules: declare a protocol with the required object, attach that object during module init.
Differential Revision: D26289581
fbshipit-source-id: 35ae83912e392be84f55c8d056c8da15ba75060f