Summary: Quick fix for layout plugin and export crashing when encountering nullable props for colors and drawables like `refreshProgressBarBackgroundColor` on `RecyclerSpec`. The rendered view in the inspector is not great right now, but better than a crash. Working on the correct representation next.
Reviewed By: jknoxville
Differential Revision: D15241151
fbshipit-source-id: 3754dee8861a442127a34d7c3211d223c5f390c1
2cdcd9bad9