add docker_image_name attribute to VSGService

Change-Id: I27cd9ffd4629823f0f9cfe17c70038c2122929fc
diff --git a/xos/synchronizer/manifest b/xos/synchronizer/manifest
index d13ee05..d15f0d8 100644
--- a/xos/synchronizer/manifest
+++ b/xos/synchronizer/manifest
@@ -3,6 +3,7 @@
 templates/before.rules.j2
 templates/start-vcpe.sh.j2
 templates/dnsmasq_safe_servers.j2
+templates/docker.j2
 templates/firewall_sample.j2
 templates/rc.local.j2
 templates/vcpe.conf.j2