[mongo] Fixes a mistake in the Mongo Collections Check (#2783)
[mongo] Fixes a mistake in the Mongo Collections Check (#2783)

* fixes a mistake in the mongo check

* fixes mongo

* skips metrics that don't exist

* puts _resolve_metric before loop

jyogi/purvar-agent,manolama/dd-agent,Wattpad/dd-agent,takus/dd-agent,cberry777/dd-agent,cberry777/dd-agent,cberry777/dd-agent,Wattpad/dd-agent,Wattpad/dd-agent,Wattpad/dd-agent,takus/dd-agent,manolama/dd-agent,manolama/dd-agent,takus/dd-agent,cberry777/dd-agent,jyogi/purvar-agent,takus/dd-agent,Wattpad/dd-agent,cberry777/dd-agent,jyogi/purvar-agent,manolama/dd-agent,jyogi/purvar-agent,manolama/dd-agent,takus/dd-agent,jyogi/purvar-agent