fix: do not restore non-installed services

Some services might not be installed (i.e. redis) if a relevant subrole
is not used (i.e. performancecopilot.metrics.redis). Thus an attempt to
restore such a service fails. This commit adds a check for the service
presence before its restoration.

tests/restore_services_state.yml

@@ -15,6 +15,7 @@
   when:
     - item + '.service' in final_state.ansible_facts.services
     - item + '.service' in initial_state.ansible_facts.services
+    - initial_state.ansible_facts.services[item + '.service'].status != "not-found"
   with_items:
     - pmcd
     - pmlogger