[Stack Monitoring] update data streams dataset section

[klacabane]

Summary

Related elastic/kibana#135382

Today the stack monitoring's package writes data to metrics-{product}.{metricset}-{namespace} but should write to metrics-{product}.stack_monitoring.{metricset}-{namespace} to be more explicit about their purpose. This will help segregate data when PO packages will deliver differently shaped documents for these products.

We can use the dataset property to specify the new one at the data stream level

• update elasticsearch metrics data streams
• update kibana metrics data streams
• update logstash metrics data streams

AC

Metrics written by stack monitoring packages are sent to metrics-{product}.stack_monitoring.{metricset}-{namespace}