opensearch: default dashboards tag to opensearch_tag

Closes-Bug: #2016627

Change-Id: I5ae1d911c5df423e0b70dab306709320083b7b69

ansible/roles/opensearch/defaults/main.yml

@@ -84,7 +84,7 @@ opensearch_tag: "{{ openstack_tag }}"
 opensearch_image_full: "{{ opensearch_image }}:{{ opensearch_tag }}"
 
 opensearch_dashboards_image: "{{ docker_registry ~ '/' if docker_registry else '' }}{{ docker_namespace }}/opensearch-dashboards"
-opensearch_dashboards_tag: "{{ openstack_tag }}"
+opensearch_dashboards_tag: "{{ opensearch_tag }}"
 opensearch_dashboards_image_full: "{{ opensearch_dashboards_image }}:{{ opensearch_dashboards_tag }}"
 
 opensearch_dimensions: "{{ default_container_dimensions }}"