MM_22682_Centralize_ID_Validation (#14237)

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

api4/command.go

@@ -296,7 +296,7 @@ func executeCommand(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if len(commandArgs.Command) <= 1 || strings.Index(commandArgs.Command, "/") != 0 || len(commandArgs.ChannelId) != 26 {
+	if len(commandArgs.Command) <= 1 || strings.Index(commandArgs.Command, "/") != 0 || !model.IsValidId(commandArgs.ChannelId) {
 		c.Err = model.NewAppError("executeCommand", "api.command.execute_command.start.app_error", nil, "", http.StatusBadRequest)
 		return
 	}