Merge branch 'pl-fix-spring-stale-activerecord' into 'master'

Fix autoload issue for "Gitlab::Metrics::Subscribers::ActiveRecord"

See merge request gitlab-org/gitlab!44842

lib/gitlab/metrics/subscribers/active_record.rb

@@ -61,7 +61,7 @@ module Gitlab
         end
 
         def current_transaction
-          Transaction.current
+          ::Gitlab::Metrics::Transaction.current
         end
       end
     end