run the gci containerized mounter to cache mounter container image

Signed-off-by: Vishnu kannan <vishnuk@google.com>

cluster/gce/gci/configure-helper.sh

@@ -1164,6 +1164,9 @@ For Kubernetes copyright and licensing information, see:
 EOF
 }
 
+function pre-warm-mounter {
+    ${KUBE_HOME}/bin/mounter &> /dev/null
+}
 
 ########### Main Function ###########
 echo "Start to configure instance for kubernetes"
@@ -1198,6 +1201,8 @@ else
   create-kubeproxy-kubeconfig
 fi
 
+# Run the containerized mounter once to pre-cache the container image.
+pre-warm-mounter
 assemble-docker-flags
 load-docker-images
 start-kubelet