### What problem does this PR solve?
An exception happens if you give session_id to agent_open_ai completion.
Because session_id is being given as well as **req so it tries to send
session_id twice. But also the logic seemed odd on picking one of
session_id, id, metadata.id. So cleaned it up a little.
See #10111
### Type of change
- [X] Bug Fix (non-breaking change which fixes an issue)