title: Supervising long lived snapshot listeners in Firestore
body: <p>I have a backend service in which I want to listen on changes in a collection for indefinite long period of time, probably for months without restart. In a <a href="https://stackoverflow.com/questions/66842111/is-there-any-time-limit-for-firestore-snapshotlisteners">related question</a>, it has been said this is not an issue.</p>
  <p>However, I want to know if there is a way to check if the connection is still alive and attach a new listener, for example, when a previous one fails.</p>