defaultPersistedState

Summary: adding a `static defaultPersistedState` which plugins can use to populate their persistedState for the first render.

Reviewed By: passy

Differential Revision: D10446987

fbshipit-source-id: eb37553db7bbec31edf5b4972176e71f303639fe

src/plugin.js

@@ -52,6 +52,7 @@ export class FlipperBasePlugin<
   static icon: string = 'apps';
   static keyboardActions: ?KeyboardActions;
   static screenshot: ?string;
+  static defaultPersistedState: PersistedState;
 
   // forbid instance properties that should be static
   title: empty;