Port PR from PBS-Java: Unruly: Include GPID in request payload

[cross-repo-issue-creation]

A PR was merged over on PBS-Java

• Unruly: Include GPID in request payload prebid-server-java#4259
• timestamp: 2025-10-31T12:29:47Z

[bsardo]

I need to check whether this behavior was already incorporated or if there is an open PR to add it.