Map Docker ports correctly in metrics.rb

lib/gitlab/qa/scenario/test/integration/metrics.rb

@@ -14,7 +14,10 @@ module Gitlab
                 gitlab.release = release
                 gitlab.network = 'test'
                 gitlab.name = 'gitlab'
-                gitlab.ports = [PUMA_METRICS_SERVER_PORT, SIDEKIQ_METRICS_SERVER_PORT]
+                gitlab.ports = [
+                  "#{PUMA_METRICS_SERVER_PORT}:#{PUMA_METRICS_SERVER_PORT}",
+                  "#{SIDEKIQ_METRICS_SERVER_PORT}:#{SIDEKIQ_METRICS_SERVER_PORT}"
+                ]
                 gitlab.omnibus_configuration << <<~RUBY
                   puma['exporter_enabled'] = true