Call getDocumentFromLocalCache:completion: on the user queue (#1652)
Call getDocumentFromLocalCache:completion: on the user queue (#1652)

* Call getDocumentFromLocalCache:completion: on the user queue
* Call getDocumentsFromLocalCache:completion: on the user queue

firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk