Adds instance metrics to usage ping

This adds influxdb_metrics_enabled and prometheus_metrics_enabled to
usage ping.

lib/gitlab/usage_data.rb

@@ -117,9 +117,11 @@ module Gitlab
           container_registry_enabled: Gitlab.config.registry.enabled,
           gitlab_shared_runners_enabled: Gitlab.config.gitlab_ci.shared_runners_enabled,
           gravatar_enabled: Gitlab::CurrentSettings.gravatar_enabled?,
+          influxdb_metrics_enabled: Gitlab::CurrentSettings.metrics_enabled?,
           ldap_enabled: Gitlab.config.ldap.enabled,
           mattermost_enabled: Gitlab.config.mattermost.enabled,
           omniauth_enabled: Gitlab::Auth.omniauth_enabled?,
+          prometheus_metrics_enabled: Gitlab::CurrentSettings.prometheus_metrics_enabled?,
           reply_by_email_enabled: Gitlab::IncomingEmail.enabled?,
           signup_enabled: Gitlab::CurrentSettings.allow_signup?
         }

spec/lib/gitlab/usage_data_spec.rb

@@ -57,6 +57,8 @@ describe Gitlab::UsageData do
         database
         avg_cycle_analytics
         web_ide_commits
+        influxdb_metrics_enabled
+        prometheus_metrics_enabled
       ))
     end