During upgrade the postinst of contrail-openstack back's up the

/etc/init.d/<openstack service> assuming that the conf file is from the
native package. Fix is to backup only if the native package upstart
file exists(meaning fresh install). If the native package upstart dosent exists
it is upgrade case.

Change-Id: I27546002e0a411285bc98ac029d8fc26d1b8b38e
Closes-Bug: 1549619

common/debian/contrail-openstack/debian/contrail-openstack.postinst

@@ -3,11 +3,16 @@ for svc in keystone nova-api nova-scheduler nova-conductor nova-console\
            nova-consoleauth nova-objectstore nova-novncproxy glance-api\
            glance-registry cinder-api cinder-scheduler heat-engine heat-api heat-api-cfn ; do
     if [ -f /etc/init/$svc.conf ]; then
+        # Service stop is required for SM provisioing; because SM does
+        # installation of contrail-openstack after provisioning
+        # with native openstack packages
         service $svc stop || true
         mv /etc/init/$svc.conf /etc/init/$svc.conf.backup
-    fi
-    if [ -f /etc/init.d/$svc ]; then
-        mv /etc/init.d/$svc /etc/init.d/$svc.backup
+        # Move only in case of fresh install, if /etc/init/$svc.conf exists
+        # it is a fresh install case
+        if [ -f /etc/init.d/$svc ]; then
+            mv /etc/init.d/$svc /etc/init.d/$svc.backup
+        fi
     fi
     if [ -f /etc/init.d/$svc.initd.supervisord ]; then
         mv /etc/init.d/$svc.initd.supervisord /etc/init.d/$svc