Persist device ID

Summary: Linked to https://github.com/facebook/flipper/issues/3319

Reviewed By: passy

Differential Revision: D36786952

fbshipit-source-id: f3214f35039845a8e35fa14e63f509a6fbdddb1f

js/js-flipper/src/index.ts

@@ -9,6 +9,7 @@
 
 import {FlipperClient} from './client';
 
+export * from './consts';
 export * from './client';
 export * from './plugin';