Signifies the start of an authentication process.
func onAuthStart(userID: String, authMethods: inout String)
This event is fired in response to a StartAuth call, and signifies the start of a (potentially, multi-step) authentication process for UserID. The AuthMethods parameter list the methods to be performed for the user. The application may customize them as needed.
The following default authentication methods are supported:
The application can define its own authentication methods if needed.
This event is only fired once per user authentication process, at the very start of it. See AuthAttemptStart for per-step notification.