azure - sql server metrics filter

[stefangordon]

Today metrics at the server level require a filter like this:

• type: metric
  metric: dtu_consumption_percent
  aggregation: average
  op: lt
  threshold: 10
  timeframe: 24
  filter: "DatabaseResourceId eq '*'"

I suspect that filter should not be required.... Maybe it should happen automatically for the server level metrics query somehow?

Similarly we need to add this same filter to make cosmos children work in #4511