Use androidEnabled setting in dispatcher

Summary:
Takes the androidEnabled setting and uses it to gate the android dispatcher.
Enables people without android sdk to use flipper (e.g. iOS engineers).

Reviewed By: priteshrnandgaonkar

Differential Revision: D17829810

fbshipit-source-id: 7d25580e65dee93ebfda7c5cc4c4cea03744e2ca

src/dispatcher/index.tsx

@@ -18,11 +18,12 @@ import user from './user';
 import {Logger} from '../fb-interfaces/Logger';
 import {Store} from '../reducers/index';
 import {Dispatcher} from './types';
+import {notNull} from '../utils/typeUtils';
 
 export default function(store: Store, logger: Logger): () => Promise<void> {
   const dispatchers: Array<Dispatcher> = [
     application,
-    androidDevice,
+    store.getState().settingsState.enableAndroid ? androidDevice : null,
     iOSDevice,
     desktopDevice,
     tracking,
@@ -30,7 +31,7 @@ export default function(store: Store, logger: Logger): () => Promise<void> {
     notifications,
     plugins,
     user,
-  ];
+  ].filter(notNull);
   const globalCleanup = dispatchers
     .map(dispatcher => dispatcher(store, logger))
     .filter(Boolean);