Defaults: replace docker with containerd as our default container_manager (#8175)

* Defaults: replace docker with containerd as our default container_manager

* CI: Use docker for download_localhost test

* Defaults: with container_manager=containerd we need etcd_deployment_type=host

* CI: Run weave jobs with docker

* CI: Vagrant don't download_force_cache

* CI: Fix upgrade tests

* should run compatible with old settings, this means docker
* we need to run with a distro that has at least modern containerd,
  this means move from debian9 to debian10 to allow `containerd_version`
  to match between 2.17 and master

tests/files/packet_debian10-calico-upgrade-once.yml

@@ -0,0 +1,17 @@
+---
+# Instance settings
+cloud_image: debian-10
+mode: default
+
+# Kubespray settings
+kube_network_plugin: calico
+deploy_netchecker: true
+dns_min_replicas: 1
+download_run_once: true
+
+# Docker specific settings:
+container_manager: docker
+etcd_deployment_type: docker
+
+# Make docker happy
+docker_containerd_version: latest