Move docker systemd unit creation to docker role

Creating the unit using default settings early on
and then changing it during network_plugin section
leads to too many docker restarts and duplicated code.

Reversed Wants= dependence on docker.service so it does not
restart docker when reloading systemd

Consolidated all docker restart handlers.

roles/network_plugin/calico/tasks/main.yml

@@ -10,13 +10,6 @@
     - restart docker
   when: ansible_os_family != "CoreOS"
 
-- name: Calico | Write docker.service systemd file
-  template:
-    src: systemd-docker.service
-    dest: /lib/systemd/system/docker.service
-  notify: restart docker
-  when: ansible_service_mgr == "systemd" and ansible_os_family != "CoreOS"
-
 - meta: flush_handlers
 
 - name: Calico | Install calicoctl container script

roles/network_plugin/calico/templates/calico-node.service.j2

@@ -2,7 +2,7 @@
 Description=Calico per-node agent
 Documentation=https://github.com/projectcalico/calico-docker
 After=docker.service docker.socket etcd-proxy.service
-Wants=docker.service docker.socket etcd-proxy.service
+Wants=docker.socket etcd-proxy.service
 
 [Service]
 User=root

roles/network_plugin/calico/templates/systemd-docker.service

@@ -1,39 +0,0 @@
-[Unit]
-Description=Docker Application Container Engine
-Documentation=http://docs.docker.com
-{% if ansible_os_family == "RedHat" %}
-After=network.target docker-storage-setup.service
-Wants=docker-storage-setup.service
-{% elif ansible_os_family == "Debian" %}
-After=network.target docker.socket
-Wants=docker.socket
-{% endif %}
-
-[Service]
-Type=notify
-{% if ansible_os_family == "RedHat" %}
-EnvironmentFile=-/etc/default/docker
-EnvironmentFile=-/etc/sysconfig/docker
-EnvironmentFile=-/etc/sysconfig/docker-network
-EnvironmentFile=-/etc/sysconfig/docker-storage
-{% elif ansible_os_family == "Debian" %}
-EnvironmentFile=-/etc/default/docker
-{% endif %}
-Environment=GOTRACEBACK=crash
-ExecReload=/bin/kill -s HUP $MAINPID
-Delegate=yes
-KillMode=process
-ExecStart=/usr/bin/docker daemon \
-          $OPTIONS \
-          $DOCKER_STORAGE_OPTIONS \
-          $DOCKER_NETWORK_OPTIONS \
-          $INSECURE_REGISTRY \
-          $DOCKER_OPTS
-LimitNOFILE=1048576
-LimitNPROC=1048576
-LimitCORE=infinity
-MountFlags=slave
-TimeoutStartSec=1min
-
-[Install]
-WantedBy=multi-user.target