[2.11] fix broken scale procedure (#5926)

* Update main.yml

- remove default value 'systemd' for cgroup driver in containerd role.
  this value override autodetect in kubelet_cgroup_driver_detected from docker info

* Update scale.yml

do not run etcd role when etcd_kubeadm_enabled == true

roles/container-engine/containerd/defaults/main.yml

@@ -1,6 +1,4 @@
 ---
-kubelet_cgroup_driver: systemd
-
 containerd_config:
   grpc:
     max_recv_message_size: 16777216