Make plugin.tsx strict
Make plugin.tsx strict

Reviewed By: danielbuechele

Differential Revision: D17228192

fbshipit-source-id: 74e5edf9dfd3260a3463e57a16d1f9c8c0399137

facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper