Fix logrotate issue on Octavia and Watcher service

Services config files are missing in cron command.
Cron Jinja template has been adapted in order to take it into account.

Change-Id: I5aef67b774ddaf83afdfe03d099b91e68a11ae1d
Closes-Bug: #1673163
Closes-Bug: #1673193

ansible/roles/common/templates/cron.json.j2

@@ -25,6 +25,7 @@
     ( 'murano', enable_murano ),
     ( 'neutron', enable_neutron ),
     ( 'nova', enable_nova ),
+    ( 'octavia', enable_octavia ),
     ( 'panko', enable_panko ),
     ( 'rabbitmq', enable_rabbitmq ),
     ( 'sahara', enable_sahara ),
@@ -32,7 +33,8 @@
     ( 'senlin', enable_senlin ),
     ( 'solum', enable_solum ),
     ( 'swift', enable_swift ),
-    ( 'tacker', enable_tacker )
+    ( 'tacker', enable_tacker ),
+    ( 'watcher', enable_watcher )
 ] %}
 {
     "command": "{{ cron_cmd }}",