Lint fix (#2578)

* Lint fix

* Update local_store.ts

Author: schmidt-sebastian

packages/firestore/src/local/local_store.ts

@@ -48,7 +48,6 @@ import { SortedMap } from '../util/sorted_map';
 import { LocalDocumentsView } from './local_documents_view';
 import { LocalViewChanges } from './local_view_changes';
 import { LruGarbageCollector, LruResults } from './lru_garbage_collector';
-import { IndexedDbRemoteDocumentCache } from './indexeddb_remote_document_cache';
 import { MutationQueue } from './mutation_queue';
 import {
   Persistence,