DoNotAllowDuplicateSetCookies http channel config option is not working

[loriadi]

Describe the bug
The http channel config property DoNotAllowDuplicateSetCookies=true, when set, still allows duplicate set-cookie cookies in http responses.

Steps to Reproduce
Set the on the httpEndPoint in server.xml. Have an application create two Set-Cookie headers with the same cookie name. When the property is set, the duplicate header should be removed from the response.

Expected behavior
The http response should not be sent with duplicate Set-Cookie cookies.

Diagnostic information:

• OpenLiberty Version: [e.g. 20.0.0.3 - 23.0.0.1]
• Affected feature(s): setvlet-4.0, servlet-3.1
• Java Version: n/a
• server.xml configuration

servlet-4.0