Don't pass meter descriptions as units

[gansb]

Description

When publishing as prometheus metrics the kafka gauge metrics are exported as

# TYPE messaging_kafka_consumer_queue_message_count_Number of ops (callbacks, events, etc) waiting in queue for application to serve with rd_kafka_poll() gauge
# UNIT messaging_kafka_consumer_queue_message_count_Number of ops (callbacks, events, etc) waiting in queue for application to serve with rd_kafka_poll() Number of ops (callbacks, events, etc) waiting in queue for application to serve with rd_kafka_poll()
messaging_kafka_consumer_queue_message_count_Number of ops (callbacks, events, etc) waiting in queue for application to serve with rd_kafka_poll()

This may be because the description is passed as a unit.

Fixes #6447

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire-docs issue:
  • No

Microsoft Reviewers: Open in CodeFlow

[gansb]

@dotnet-policy-service agree

[mitchdenny]

@samsp-msft @JamesNK

[JamesNK]

Looks like a cut and dried bug. Second argument is unit, not description.

https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.metrics.meter.createcounter?view=net-8.0#system-diagnostics-metrics-meter-createcounter-1(system-string-system-string-system-string)

[eerhardt]

It would be good to have a test. Can be done as a follow up.

[davidfowl]

Does this need to be backported?

[JamesNK]

@gansb Thanks for the fix!

@eerhardt Can you manage getting this backported to 9.0?

[davidfowl]

/backport to release/9.0

[github-actions]

Started backporting to release/9.0: https://github.com/dotnet/aspire/actions/runs/11492020195