m/n/k/containerd: use preseeded pause container

To allow no-network tests we need to bundle the pause container.

Change-Id: I1fa6bb70c10a16097d35d919941f501ddc5f784d
Reviewed-on: https://review.monogon.dev/c/monogon/+/2767
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/node/kubernetes/containerd/config.toml b/metropolis/node/kubernetes/containerd/config.toml
index f033b27..4f6e31c 100644
--- a/metropolis/node/kubernetes/containerd/config.toml
+++ b/metropolis/node/kubernetes/containerd/config.toml
@@ -53,7 +53,7 @@
     stream_server_port = "0"
     stream_idle_timeout = "4h0m0s"
     enable_selinux = false
-    sandbox_image = "k8s.gcr.io/pause:3.1"
+    sandbox_image = "preseed.metropolis.internal/node/kubernetes/pause:latest"
     stats_collect_period = 10
     systemd_cgroup = false
     enable_tls_streaming = false