Move Ansible roles dir to main dir; add condition to deploy OpenSearch

If someone would like to re-use provided roles in Zuul, according to the
doc [1], it would be good behaviour to set the `roles` dir in the main
project dir.
Also added a condition to deploy OpenSearch if needed to verify
logscraper workflow.

[1] https://zuul-ci.org/docs/zuul/latest/config/job.html#attr-job.roles

Change-Id: Ic8b7e2a400fb7f5c37a676236fd7ccd202a5d5f5

ansible/roles

@@ -0,0 +1 @@
+../roles

roles/check-services/tasks/main.yml

@@ -4,6 +4,7 @@
 
 - name: Configure OpenSearch
   ansible.builtin.include_tasks: opensearch.yml
+  when: deploy_opensearch | default(true)
 
 - name: Configure log processing services
   ansible.builtin.include_tasks: logprocessing.yml