Feature Request: Convert the room_id string in the webex_config to a secret value.

[AkshayAwate]

The room_id in the Webex configuration is a confidential parameter, but in the Prometheus documentation, it is expected as a string (as seen here: Prometheus Docs and webex.go), making it vulnerable on the internet. It would be more secure to include it under authorization within http_config, allowing it to be sourced from Kubernetes secrets.