Add tracing to usage stats

ee/changelogs/unreleased/8318-add-tracing-usage-stats.yml

+---
+title: Add count of projects with tracing enabled to usage ping data
+merge_request: 8940
+author:
+type: other

ee/lib/ee/gitlab/usage_data.rb

@@ -101,7 +101,8 @@ module EE
           projects_reporting_ci_cd_back_to_github: count(::GithubService.without_defaults.active),
           projects_mirrored_with_pipelines_enabled: projects_mirrored_with_pipelines_enabled,
           projects_with_prometheus_alerts: count(PrometheusAlert.distinct_projects),
-          projects_with_packages: count(::Packages::Package.select('distinct project_id'))
+          projects_with_packages: count(::Packages::Package.select('distinct project_id')),
+          projects_with_tracing_enabled: count(ProjectTracingSetting)
         }).merge(service_desk_counts).merge(security_products_usage)
 
         usage_data

ee/spec/lib/gitlab/usage_data_spec.rb

@@ -22,6 +22,8 @@ describe Gitlab::UsageData do
       create(:package, project: projects[0])
       create(:package, project: projects[0])
       create(:package, project: projects[1])
+
+      create(:project_tracing_setting, project: projects[0])
     end
 
     subject { described_class.data }
@@ -64,6 +66,7 @@ describe Gitlab::UsageData do
         sast_jobs
         projects_with_prometheus_alerts
         projects_with_packages
+        projects_with_tracing_enabled
       ))
 
       expect(count_data[:projects_with_prometheus_alerts]).to eq(2)