Improve DistinctCountByLargeForeignKey cop

- Removes UsageData/DistinctCountByLargeForeignKey for some metrics
- Puts allowed foreign keys in alphabetical order Improves
- Cop to accept both string and symbol arguments

lib/gitlab/usage_data.rb

@@ -815,11 +815,9 @@ module Gitlab
       end
 
       # rubocop: disable CodeReuse/ActiveRecord
-      # rubocop: disable UsageData/DistinctCountByLargeForeignKey
       def cluster_applications_user_distinct_count(applications, time_period)
         distinct_count(applications.where(time_period).available.joins(:cluster), 'clusters.user_id')
       end
-      # rubocop: enable UsageData/DistinctCountByLargeForeignKey
 
       def clusters_user_distinct_count(clusters, time_period)
         distinct_count(clusters.where(time_period), :user_id)

rubocop/cop/usage_data/distinct_count_by_large_foreign_key.rb

@@ -31,11 +31,11 @@ module RuboCop
         private
 
         def allowed_foreign_key?(key)
-          [:sym, :str].include?(key.type) && allowed_foreign_keys.include?(key.value.to_sym)
+          [:sym, :str].include?(key.type) && allowed_foreign_keys.include?(key.value.to_s)
         end
 
         def allowed_foreign_keys
-          cop_config['AllowedForeignKeys'] || []
+          (cop_config['AllowedForeignKeys'] || []).map(&:to_s)
         end
       end
     end

rubocop/rubocop-usage-data.yml

@@ -38,12 +38,13 @@ UsageData/DistinctCountByLargeForeignKey:
     - 'lib/gitlab/usage_data.rb'
     - 'ee/lib/ee/gitlab/usage_data.rb'
   AllowedForeignKeys:
-    - :user_id
-    - :author_id
-    - :creator_id
-    - :owner_id
-    - :project_id
-    - :issue_id
-    - :merge_request_id
-    - :merge_requests.target_project_id
-    - :agent_id
+    - 'agent_id'
+    - 'author_id'
+    - 'clusters.user_id'
+    - 'creator_id'
+    - 'issue_id'
+    - 'merge_request_id'
+    - 'merge_requests.target_project_id'
+    - 'owner_id'
+    - 'project_id'
+    - 'user_id'