Adjust virtlet-ds for v1.1.1

Change-Id: Ia4131ea863ca2b00abbfb3cc653344364e1f5021
diff --git a/kubernetes/files/kube-addons/virtlet/virtlet-ds.yml b/kubernetes/files/kube-addons/virtlet/virtlet-ds.yml
index 7a2372e..beb4535 100644
--- a/kubernetes/files/kube-addons/virtlet/virtlet-ds.yml
+++ b/kubernetes/files/kube-addons/virtlet/virtlet-ds.yml
@@ -2,7 +2,7 @@
 {%- from "kubernetes/map.jinja" import master with context -%}
 {%- from "kubernetes/map.jinja" import version %}
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: DaemonSet
 metadata:
   creationTimestamp: null
@@ -18,6 +18,9 @@
         runtime: virtlet
       name: virtlet
     spec:
+      selector:
+        matchLabels:
+          runtime: virtlet
       hostNetwork: true
       dnsPolicy: ClusterFirstWithHostNet
       # hostPID is true to (1) enable VMs to survive virtlet container restart