[MetricsAdvisor] Update live anomaly/alert config tests to use newly created data feed

[kinelski]

Sharing the same data feed across multiple languages can be problematic because there's a limit of how many configs we can create. If we reach the limit (10), we get the following error back from the service:

{"code":"Bad Request","message":"Invalid parameter. config count should be less than or equal to 10. TraceId: b29a4c4f-3357-4198-91cc-5541507ad822"}

We also need to decide what to do with our samples. It may not be a good idea to create mock entities for them, as we want to make sure users can run them with actual data. As part of this issue, we'll also need to re-enable the sample:

• CreateAndDeleteDetectionConfigurationAsync (moved to [MetricsAdvisor] Re-enable "create config" samples #22575).

[kinelski]

Fixed by #21823 and #21748. Sample work moved to #22575.