add systemd drop-in conf for osbs docker

Signed-off-by: Adam Miller <admiller@redhat.com>

files/osbs/docker.custom.service

@@ -0,0 +1,8 @@
+# Ansible managed
+
+[Unit]
+Wants=iptables.service
+After=iptables.service
+
+[Service]
+ExecStartPost=/usr/local/bin/fix-docker-iptables

playbooks/groups/osbs-orchestrator-cluster.yml

@@ -697,8 +697,8 @@
 
     - name: copy docker service config
       copy:
-        src: "{{files}}/osbs/docker.service"
+        src: "{{files}}/osbs/docker.custom.service"
-        dest: /etc/systemd/system/docker.service
+        dest: /etc/systemd/system/docker.service.d/custom.conf
       notify:
         - systemctl daemon-reload
         - restart docker