[monitor-query] Tracking issue to make the metricNames required in swagger

The metricNames should probably be required in the swagger - for queryMetrics Method - `metrics.list` in the swagger
cc: @srnagar

Start by locating the monitor-query Swagger definition for the queryMetrics method, specifically metrics.list, and inspect how metricNames is declared. Done means the specification marks metricNames as required and the relevant specification validation passes.

Written by the indexing model from the issue text.