Bug 1315563 - Upgrade failed to containerized install OSE 3.1 on RHEL

Previously I was greping for 'ose' in the systemd units.  That was only working
on my machine because my Nodes were also Masters.  It's safer to grep for
openshift3 since that would be present for Masters or Nodes.

playbooks/common/openshift-cluster/upgrades/files/openshift_container_versions.sh

@@ -10,7 +10,7 @@ if [ ${1} == "origin" ]; then
     image_name="openshift/origin"
 elif grep aep $unit_file 2>&1 > /dev/null; then
     image_name="aep3/aep"
-elif grep ose $unit_file 2>&1 > /dev/null; then
+elif grep openshift3 $unit_file 2>&1 > /dev/null; then
     image_name="openshift3/ose"
 fi