Flush telemetry on supervisor agent error

[ranweiler]

Summary of the Pull Request

Flush telemetry when supervisor agent exits due to an error.

PR Checklist

• Applies to work item: Supervisor telemetry not flushed on error #20
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Validation Steps Performed

• Tested manually.