[Feature Request] Increase http.max_header_size default to 16kb

[10000-ki]

Is your feature request related to a problem? Please describe

Our current default max header size is 8KB.

opensearch-project/security-dashboards-plugin#1311 (comment)

When using JWT token-based authentication, an 8KB header size is insufficient.
Elasticsearch encountered the same issue and has increased the default value to 16KB.
see : elastic/elasticsearch#88725

Unless there are any particular concerns, I suggest we do the same and change our default to 16KB as well.

Describe the solution you'd like

increase to 16kb

Related component

Other

Describe alternatives you've considered

No response

Additional context

No response

[jainankitk]

@10000-ki - Thank you for reporting this issue. I see you have a PR linked already!