Ensure service is restarted on unit file changes

At the moment we don't restart services if systemd unit file is changed.

We knowingly prevent systemd_service role handlers to execute
by providing `state: started` as otherwise service will be restarted twice.
With that now  we ensure that role handlers will also listen for systemd
unit changes.

Change-Id: I8ce4f18e853ee0c55970012f4c40574960607441

handlers/main.yml

@@ -26,6 +26,7 @@
   delay: 2
   listen:
     - Restart adjutant services
+    - systemd service changed
 
 - name: Start services
   service:
@@ -42,3 +43,4 @@
   delay: 2
   listen:
     - Restart adjutant services
+    - systemd service changed

tasks/main.yml

@@ -119,8 +119,8 @@
     systemd_TasksAccounting: true
     systemd_services:
       - service_name: "{{ service_var.service_name }}"
-        enabled: yes
-        state: started
+        enabled: "{{ service_var.enabled | default(True) }}"
+        state: "{{ service_var.state | default('started') }}"
         execstarts: "{{ service_var.execstarts }}"
         execreloads: "{{ service_var.execreloads | default([]) }}"
         config_overrides: "{{ service_var.init_config_overrides }}"