[MM-57010] Include client type in websocket connections metric (#26763)

* Include client type in websocket connections metric

* Unexport field

server/channels/api4/websocket.go

@@ -11,6 +11,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
 	"github.com/mattermost/mattermost/server/v8/channels/app/platform"
+	"github.com/mattermost/mattermost/server/v8/channels/web"
 )
 
 const (
@@ -48,6 +49,13 @@ func connectWebSocket(c *Context, w http.ResponseWriter, r *http.Request) {
 		Locale:    "",
 		Active:    true,
 	}
+	// The WebSocket upgrade request coming from mobile is missing the
+	// user agent so we need to fallback on the session's metadata.
+	if c.AppContext.Session().IsMobileApp() {
+		cfg.OriginClient = "mobile"
+	} else {
+		cfg.OriginClient = string(web.GetOriginClient(r))
+	}
 
 	cfg.ConnectionID = r.URL.Query().Get(connectionIDParam)
 	if cfg.ConnectionID == "" || c.AppContext.Session().UserId == "" {