Custom parameter in Quickblox notification chatroom IOS to android

Hello everyone i am creating chat application using Quickblox, I have followed the instruction below:

Create APNS certificate and upload it to the Admin panel

http://ift.tt/1vIBFw6

Subscribe users to push notifications

http://ift.tt/1xwMZ4x

I have set the notification as following way

aps =     {

alert = "user one says hi in group";
};
"dialog_id" = 54a3ee0a535c12ea3f01b89f;
"qb_chat_type" = QBGroupChat;
"qb_message_text" = hi;
"qb_message_type" = text;
"qb_sender_image" = "";
"qb_sender_name" = "Neeta khurana";
"tab_group_id" = 200;
"user_id" = 2101266;
}

But the quickblox send 2 notifications in group chat one is above that i have set and another is below:

aps =    {
alert = "You have 15 new messages";
sound = 1;
};
"dialog_id" = 54a3ee0a535c12ea3f01b89f;
"user_id" = 2101266;
}

So i don't want the notification generated automatically by quickblox and for android device the notification not appears. can anybody help to sort out this.