fix(afs): Remove DocumentListenOptions

Author: davideast

src/firestore/interfaces.ts

@@ -12,7 +12,7 @@ export interface Action<T> {
 };
 
 export interface Reference<T> {
-  onSnapshot: (options: firebase.firestore.DocumentListenOptions, sub: Subscriber<any>) => any;
+  onSnapshot: (sub: Subscriber<any>) => any;
 }
 
 // A convience type for making a query.

src/firestore/observable/fromRef.ts

@@ -9,7 +9,7 @@ import 'rxjs/add/operator/map';
 
 function _fromRef<T, R>(ref: Reference<T>): Observable<R> {
   const ref$ = new Observable(subscriber => {
-    const unsubscribe = ref.onSnapshot({ includeQueryMetadataChanges: true }, subscriber);
+    const unsubscribe = ref.onSnapshot(subscriber);
     return { unsubscribe };
   });
   return observeOn.call(ref$, new ZoneScheduler(Zone.current));