The default behavior. The listener attempts to return initial snapshot from cache and retrieve
up-to-date snapshots from the Firestore server. Snapshot events will be triggered on local
mutations and server-side updates.
The listener retrieves data and listens to updates from the local Firestore cache without
attempting to send the query to the server. If some documents gets updated as a result from
other queries, they will be picked up by listeners using the cache.
Note that the data might be stale if the cache hasn’t synchronized with recent server-side
changes.