OpenSearch services are restarted when no configuration change is made

When deploying current master (Rocky 9 host), I noticed that on consecutive runs OpenSearch services are restarted, even though no config change has been made. This is caused by the 'Check opensearch containers' task returning that opensearch-dashboards has changed:

```
ok: [controller0] => (item={'key': 'opensearch', 'value': {'container_name': 'opensearch', 'group': 'opensearch', 'enab
led': True, 'image': '192.168.33.3:4000/openstack.kolla/opensearch:210723-1-rocky-9', 'environment': {'OPENSEARCH_JAVA_
OPTS': '-Xms1g -Xmx1g -Dlog4j2.formatMsgNoLookups=true'}, 'volumes': ['/etc/kolla/opensearch/:/var/lib/kolla/config_fil
es/', '/etc/localtime:/etc/localtime:ro', '', 'opensearch:/var/lib/opensearch/data', 'kolla_logs:/var/log/kolla/'], 'di
mensions': {'ulimits': {'nofile': {'soft': 1048576, 'hard': 1048576}}}, 'healthcheck': {'interval': '30', 'retries': '3
', 'start_period': '5', 'test': ['CMD-SHELL', 'healthcheck_curl http://192.168.33.3:9200'], 'timeout': '30'}, 'haproxy'
: {'opensearch': {'enabled': True, 'mode': 'http', 'external': False, 'port': '9200', 'frontend_http_extra': ['option d
ontlog-normal']}}}})

changed: [controller0] => (item={'key': 'opensearch-dashboards', 'value': {'container_name': 'opensearch_dashboards', '
group': 'opensearch-dashboards', 'enabled': True, 'environment': {'OPENSEARCH_DASHBOARDS_SECURITY_PLUGIN': 'False'}, 'i
mage': '192.168.33.3:4000/openstack.kolla/opensearch-dashboards:210723-1-rocky-9', 'volumes': ['/etc/kolla/opensearch-d
ashboards/:/var/lib/kolla/config_files/:ro', '/etc/localtime:/etc/localtime:ro', '', 'kolla_logs:/var/log/kolla/'], 'di
mensions': {'ulimits': {'nofile': {'soft': 1048576, 'hard': 1048576}}}, 'healthcheck': {'interval': '30', 'retries': '3
', 'start_period': '5', 'test': ['CMD-SHELL', 'healthcheck_curl http://192.168.33.3:5601'], 'timeout': '30'}, 'haproxy'
: {'opensearch-dashboards': {'enabled': True, 'mode': 'http', 'external': False, 'port': '5601', 'auth_user': 'opensear
ch', 'auth_pass': 'foo'}, 'opensearch_dashboards_external': {'enabled': True, 'mod
e': 'http', 'external': True, 'port': '5601', 'auth_user': 'opensearch', 'auth_pass': 'foo'}}}})

```

Then:

```
RUNNING HANDLER [opensearch : Restart opensearch container] *********************
changed: [controller0]

RUNNING HANDLER [opensearch : Restart opensearch-dashboards container] **********
changed: [controller0]
```

Even if something /has/ changed with OpenSearch Dashboards, we shouldn't restart OpenSearch.