[core] fix ordering between mesos and k8s tasks transitions

Author: justonedev1

core/task/manager.go

@@ -911,17 +911,17 @@ func (m *Manager) transitionTasks(envId uid.ID, tasks Tasks, src string, event s
 		}
 	}
 
-	if len(mesosTasks) == 0 {
-		return nil
-	}
-
 	if len(tasks) != len(mesosTasks) {
 		log.WithField("partition", envId).Infof("Transitioning k8s environment from %s, to %s, event: %s", src, dest, event)
 		if err := m.transitionAndWaitK8sEnvState(context.Background(), envId, strings.ToLower(dest)); err != nil {
 			return err
 		}
 	}
 
+	if len(mesosTasks) == 0 {
+		return nil
+	}
+
 	tasks = mesosTasks
 
 	notify := make(chan controlcommands.MesosCommandResponse)