fix(k8s) keep tunnel alive for websocket connection EE-1690 (#5679)

* fix(k8s) EE-1690 keep tunnel alive for websocket connection

* fix(k8s) EE-1690 fix comment

Co-authored-by: Simon Meng <simon.meng@portainer.io>

api/http/handler/websocket/proxy.go

@@ -35,6 +35,9 @@ func (handler *Handler) proxyEdgeAgentWebsocketRequest(w http.ResponseWriter, r
 	}
 
 	handler.ReverseTunnelService.SetTunnelStatusToActive(params.endpoint.ID)
+
+	handler.ReverseTunnelService.KeepTunnelAlive(params.endpoint.ID, r.Context(), portainer.WebSocketKeepAlive)
+
 	proxy.ServeHTTP(w, r)
 
 	return nil