add network plugin metrics

Add network plugin metrics.

The metrics are the same that were used in dockershim/kubelet until
it was deprecated in kubernetes 1.23

https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/kubelet/dockershim/network/metrics/metrics.go

Signed-off-by: Antonio Ojea <aojea@google.com>

pkg/cri/sbserver/sandbox_run.go

@@ -340,8 +340,12 @@ func (c *criService) setupPodNetwork(ctx context.Context, sandbox *sandboxstore.
 		return fmt.Errorf("get cni namespace options: %w", err)
 	}
 	log.G(ctx).WithField("podsandboxid", id).Debugf("begin cni setup")
+	netStart := time.Now()
 	result, err := netPlugin.Setup(ctx, id, path, opts...)
+	networkPluginOperations.WithValues(networkSetUpOp).Inc()
+	networkPluginOperationsLatency.WithValues(networkSetUpOp).UpdateSince(netStart)
 	if err != nil {
+		networkPluginOperationsErrors.WithValues(networkSetUpOp).Inc()
 		return err
 	}
 	logDebugCNIResult(ctx, id, result)