The ActivitySessionJoinedEvent is fired when a remote session joins an Activity.
The Activity that this event relates to.
Will be true if this event is from the local user / session; false otherwise.
The name of the event that was fired. Note that the name is only guaranteed to be unique within the class / subsystem that is firing it. Names might be reused across classes and subsystems.
The participant that this event relates to.
The session id of the session that originated this event.
The username of the user originated this event.
The event name that all instances of this class will use.