OptionalappOptionalcollectionOptionalcollectionsAn array of collection names, should match the length of docs field.
OptionalconfigOptionaldocsAn array of doc names, should match the length of collections field,
or undefined if the collections field has a length of 1. In this case,
it will default to use sessionId as the doc name.
Interface for FirestoreDBChatMessageHistory. It includes the collection name, session ID, user ID, and optionally, the app index and configuration for the Firebase app.