Update virtlet-ds.yml

Latest virtlet doesn't work with old daemonset. So, to support
latest virtlet we need to update it.
Also adding a condition for mountPropagation=True in kube-apiserver
for kube >=1.8

Change-Id: I2644445553a512f639e522fcf887eb1fa34d0b12
Repated-prod: PROD-17851
diff --git a/kubernetes/files/kubelet/default.pool b/kubernetes/files/kubelet/default.pool
index e8382ac..79586f3 100644
--- a/kubernetes/files/kubelet/default.pool
+++ b/kubernetes/files/kubelet/default.pool
@@ -14,6 +14,9 @@
 --v={{ pool.get('verbosity', 2) }} \
 {%- if version|float >= 1.8 %}
 --fail-swap-on={{ pool.kubelet.fail_on_swap }} \
+{%- if common.addons.get('virtlet', {}).get('enabled') %}
+--feature-gates=MountPropagation=true \
+{%- endif %}
 {%- endif %}
 {%- if pillar.kubernetes.master is defined %}
 --node-labels=node-role.kubernetes.io/master=true \