libcontainerd: switch generated containerd.toml to v2 (v1 is deprecated)

Before this patch:

    INFO[2022-07-27T14:30:06.188762628Z] Starting up
    INFO[2022-07-27T14:30:06.190750725Z] libcontainerd: started new containerd process  pid=2028
    ...
    WARN[0000] containerd config version `1` has been deprecated and will be removed in containerd v2.0, please switch to version `2`, see https://github.com/containerd/containerd/blob/main/docs/PLUGINS.md#version-header
    INFO[2022-07-27T14:30:06.220024286Z] starting containerd                           revision=10c12954828e7c7c9b6e0ea9b0c02b01407d3ae1 version=v1.6.6

With this patch:

    INFO[2022-07-27T14:28:04.025543517Z] Starting up
    INFO[2022-07-27T14:28:04.027447105Z] libcontainerd: started new containerd process  pid=1377
    ...
    INFO[2022-07-27T14:28:04.054483270Z] starting containerd                           revision=10c12954828e7c7c9b6e0ea9b0c02b01407d3ae1 version=v1.6.6

And the generated /var/run/docker/containerd/containerd.toml:

```toml
disabled_plugins = ["io.containerd.grpc.v1.cri"]
imports = []
oom_score = 0
plugin_dir = ""
required_plugins = []
root = "/var/lib/docker/containerd/daemon"
state = "/var/run/docker/containerd/daemon"
temp = ""
version = 2

[cgroup]
  path = ""

[debug]
  address = "/var/run/docker/containerd/containerd-debug.sock"
  format = ""
  gid = 0
  level = "debug"
  uid = 0

[grpc]
  address = "/var/run/docker/containerd/containerd.sock"
  gid = 0
  max_recv_message_size = 16777216
  max_send_message_size = 16777216
  tcp_address = ""
  tcp_tls_ca = ""
  tcp_tls_cert = ""
  tcp_tls_key = ""
  uid = 0

[metrics]
  address = ""
  grpc_histogram = false

[plugins]

[proxy_plugins]

[stream_processors]

[timeouts]

[ttrpc]
  address = ""
  gid = 0
  uid = 0
```

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cmd/dockerd/daemon.go

@@ -596,7 +596,7 @@ func (cli *DaemonCli) getContainerdDaemonOpts() ([]supervisor.DaemonOpt, error)
 	}
 
 	if !cli.Config.CriContainerd {
-		opts = append(opts, supervisor.WithPlugin("cri", nil))
+		opts = append(opts, supervisor.WithPlugin("io.containerd.grpc.v1.cri", nil))
 	}
 
 	return opts, nil

libcontainerd/supervisor/remote_daemon.go

@@ -62,8 +62,9 @@ func Start(ctx context.Context, rootDir, stateDir string, opts ...DaemonOpt) (Da
 		rootDir:  rootDir,
 		stateDir: stateDir,
 		Config: config.Config{
-			Root:  filepath.Join(rootDir, "daemon"),
-			State: filepath.Join(stateDir, "daemon"),
+			Version: 2,
+			Root:    filepath.Join(rootDir, "daemon"),
+			State:   filepath.Join(stateDir, "daemon"),
 		},
 		Plugins:       make(map[string]interface{}),
 		daemonPid:     -1,