containerd support (#4664)

* Add limited containerd support

Containerd support for Ubuntu + Calico

* Added CRI-O support for ubuntu

* containerd support.

* Reset  containerd support.

* fix lint.

* implemented feedback

* Change task name cri xx instead of cri-o in reset task and timeout condition.

* set crictl to fixed version

* Use docker-ce's container.io package for containerd.

* Add check containerd is installable or not.

* Avoid stop docker when use containerd and optimize retry for reset.

* Add config.toml.

* Fixed containerd for kubelet.env.

* Merge PR #4629

* Remove unused ubuntu variable for containerd

* Polish code for containerd and cri-o

* Refactoring cri socket configuration.

* Configurable conmon.

* Remove unused crictl/runc download

* Now crictl and runc is downloaded by common crictl.yml.

* fixed yamllint error

* Fixed brokenfiles by conflict.

* Remove commented line in config.toml

* Remove readded v1.12.x version

* Fixed broken set_docker_image_facts

* Fix yamllint errors.

* Remove unused apt source

* Fix crictl could not be installed

* Add containerd config from skolekonov's PR #4601

inventory/sample/group_vars/k8s-cluster/k8s-cluster.yml

@@ -145,7 +145,7 @@ skydns_server_secondary: "{{ kube_service_addresses|ipaddr('net')|ipaddr(4)|ipad
 dns_domain: "{{ cluster_name }}"
 
 ## Container runtime
-## docker for docker and crio for cri-o.
+## docker for docker, crio for cri-o and containerd for containerd.
 container_manager: docker
 
 ## Settings for containerized control plane (etcd/kubelet/secrets)