fix: do not set empty tls_protocols_allowed and tls_ciphers for es

[nielstholenaar]

What does this PR do?

This PR resolves an issue with the Elasticsearch integration, that prevented the integration from working when there are no values passed for tls_protocols_allowed or tls_ciphers.

Motivation

When not passing any values for the tls_protocols_allowed or tls_ciphers the following config is being generated:

--- /etc/datadog-agent/conf.d/elastic.d/conf.yaml
+++ /tmp/puppet-file20250314-2365624-ndvht2
@@ -8,3 +8,5 @@
       index_stats: true
       pshard_stats: false
       pending_task_stats: true
+      tls_protocols_allowed:
+      tls_ciphers:

This result in the error below:

2025-03-14 14:26:58 CET | CORE | ERROR | (pkg/collector/worker/check_logger.go:71 in Error) | check:elastic | Error running check: [{"message":"'NoneType' object is not iterable","traceback":"Traceback (most recent call last):\n  File \"/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/base/checks/base.py\", line 1301, in run\n    self.check(instance)\n  File \"/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/elastic/elastic.py\", line 141, in check\n    stats_data = self._get_data(stats_url)\n                 ^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/elastic/elastic.py\", line 336, in _get_data\n    resp = self.http.get(url)\n           ^^^^^^^^^\n  File \"/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/base/checks/base.py\", line 400, in http\n    self._http = RequestsWrapper(self.instance or {}, self.init_config, self.HTTP_CONFIG_REMAPPER, self.log)\n                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/base/utils/http.py\", line 324, in __init__\n    for protocol in config['tls_protocols_allowed']:\n                    ~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^\nTypeError: 'NoneType' object is not iterable\n"}]

Additional Notes

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