Make swagger header params lower case to address header case sensitivity issue

[Akila94]

Description

The fix done with PR: https://github.com/wso2-support/carbon-apimgt/pull/5299 should be back ported to APIM 3.1.0 to address the same issue in it.

Steps to Reproduce

When a header param is defined in upper case in the swagger file, we cannot send a lower case header in a request when the schema validation is enabled.

Affected Component

APIM

Version

3.1.0

Environment Details (with versions)

No response

Relevant Log Output

No response

Related Issues

Related OB issue: https://github.com/wso2-enterprise/wso2-ob-internal/issues/771

Suggested Labels

No response