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: I802ebfbdec5140b2414086c04ae1297868ec256b

handlers/main.yml

@@ -27,3 +27,4 @@
   listen:
     - "Restart uwsgi services"
     - "venv changed"
+    - "systemd service changed"

tasks/uwsgi_post_install.yml

@@ -44,8 +44,8 @@
     systemd_TasksAccounting: true
     systemd_services:
       - service_name: "{{ service_var.value.service_name | default(service_var.key) }}"
-        enabled: yes
-        state: started
+        enabled: "{{ service_var.value.enabled | default(True) }}"
+        state: "{{ service_var.value.state | default('started') }}"
         execstarts: "{{ uwsgi_bin }}/uwsgi --autoload --ini /etc/uwsgi/{{ service_var.key }}.ini {{ (service_var.value.uwsgi_pyargv is defined) | ternary('--pyargv  \"' ~ service_var.value.uwsgi_pyargv | default('') ~ '\"', '') }}"
         execreloads: "{{ uwsgi_bin }}/uwsgi --reload {{ uwsgi_run_dir }}/{{ service_var.key }}/{{ uwsgi_system_slice_name }}/{{ service_var.key }}.pid"
         config_overrides: "{{ service_var.value.init_config_overrides | default({}) | combine(uwsgi_init_config_overrides, recursive=True) }}"