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/scripts/md-table/main.py

@@ -41,7 +41,6 @@ class Data:
         operating_systems = list(self.db.get_unique_ids("operating_system"))
 
         container_engines.sort()
-        container_engines.reverse() # reverse sort container_engines to get Docker first in the list
         network_plugins.sort()
         operating_systems.sort()
 
@@ -88,7 +87,7 @@ files = p.glob('*.yml')
 for f in files:
     y = yaml.load(f.open(), Loader=yaml.FullLoader)
 
-    container_manager = y.get('container_manager', 'docker')
+    container_manager = y.get('container_manager', 'containerd')
     network_plugin = y.get('kube_network_plugin', 'calico')
     x = re.match(r"^[a-z-]+_([a-z0-9]+).*", f.name)
     operating_system = x.group(1)