searchIncomingCallPendingIntent    
  open override fun searchIncomingCallPendingIntent(callId: StreamCallId, notificationId: Int, payload: Map<String, Any?>): PendingIntent?
Search for an activity that can receive incoming calls from Stream Server.
Parameters
callId 
The call id from the incoming call.
notificationId 
the notification ID.
payload
The payload from Push Notification