Add platform information for push notification metrics (#27460)

* Add platform information for push notification metrics

* Address feedback

* Add the client platform returned by the devices to the normalize function

* Add "no platform" platform label to distinguish from unknown

server/channels/wsapi/system.go

@@ -36,7 +36,7 @@ func (api *API) websocketNotificationAck(req *model.WebSocketRequest) (map[strin
 	)
 
 	// Count metrics for websocket acks
-	api.App.CountNotificationAck(model.NotificationTypeWebsocket)
+	api.App.CountNotificationAck(model.NotificationTypeWebsocket, model.NotificationNoPlatform)
 
 	status := req.Data["status"]
 	reason := req.Data["reason"]
@@ -57,6 +57,7 @@ func (api *API) websocketNotificationAck(req *model.WebSocketRequest) (map[strin
 		notificationStatus,
 		model.NotificationTypeWebsocket,
 		notificationReason,
+		model.NotificationNoPlatform,
 	)
 
 	return nil, nil