Make changes related to shift of agg metrics

Update spec file location and docs

config/metrics/aggregates/common.yml

-# Aggregated metrics that include EE only event names within `events:` attribute have to be defined at ee/lib/gitlab/usage_data_counters/aggregated_metrics/common.yml
+# Aggregated metrics that include EE only event names within `events:` attribute have to be defined at ee/config/metrics/aggregates/common.yml
 # instead of this file.
 #- name: unique name of aggregated metric
 #  operator: aggregation operator. Valid values are:

doc/development/usage_ping/index.md

@@ -1111,7 +1111,7 @@ end
 #### Add new aggregated metric definition
 
 After all metrics are persisted, you can add an aggregated metric definition at
-[`aggregated_metrics/`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/usage_data_counters/aggregated_metrics/).
+[`aggregated_metrics/`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/metrics/aggregates/).
 
 To declare the aggregate of metrics collected with [Estimated Batch Counters](#estimated-batch-counters),
 you must fulfill the following requirements: