Summary:
See previous diff, plugins that are not available during the initial client connection setup didn't show up in the UI, until selecting another device first. This diff fixes that by listening to the `plugins-change` event of the client.
Changelog: Fix issue where React Native plugins didn't show up in the Sandy layout
Reviewed By: passy
Differential Revision: D25755812
fbshipit-source-id: d865d912ecca85d868831c4da7c56b5f0be6c3bf
ef3da0e530