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: I4ebae4853fc0bc2840d3ea79546f10a12051bea9

defaults/main.yml

@@ -142,6 +142,7 @@ tacker_services:
     group: tacker_server
     service_name: "{{ tacker_conductor_program_name }}"
     enabled: yes
+    state: started
     execstarts: "{{ tacker_bin }}/{{ tacker_conductor_program_name }} {{ tacker_conductor_config_options|default('') }}"
     config_overrides: "{{ tacker_conductor_init_config_overrides }}"
 

handlers/main.yml

@@ -17,9 +17,13 @@
 
 - name: Restart tacker services
   service:
-    name: "{{ tacker_service_name }}"
+    name: "{{ item }}"
     enabled: yes
     state: restarted
     daemon_reload: yes
+  with_items:
+    - "{{ tacker_service_name }}"
+    - "{{ tacker_conductor_program_name }}"
   listen:
     - "venv changed"
+    - "systemd service changed"