ECDS stats reuse stale listener stat prefix

[kyessenov]

Per #19630, ECDS stat prefix is set from the first listener that creates a subscription. If that listener is deleted and the subscription is still active because other listeners use it, ECDS stat prefix continue referring to the deleted first listener.

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted" or "no stalebot". Thank you for your contributions.

[kyessenov]

no stalebot