Add telemetry for instance-level and template integrations

To measure the adoption of the new instance-level integration settings,
we need to add data to usage ping that lets us know how many instances
have a given integration enabled at the instance-level. We also need to
track the template usage to measure the transition.

changelogs/unreleased/204802-instances-208308-templates-usage-data.yml

+---
+title: Add telemetry for instance-level and template integrations
+merge_request: 38459
+author:
+type: other

lib/gitlab/usage_data.rb

@@ -356,6 +356,8 @@ module Gitlab
         # rubocop: disable UsageData/LargeTable:
         Service.available_services_names.each_with_object({}) do |service_name, response|
           response["projects_#{service_name}_active".to_sym] = count(Service.active.where(template: false, instance: false, type: "#{service_name}_service".camelize))
+          response["templates_#{service_name}_active".to_sym] = count(Service.active.where(template: true, type: "#{service_name}_service".camelize))
+          response["instances_#{service_name}_active".to_sym] = count(Service.active.where(instance: true, type: "#{service_name}_service".camelize))
         end.merge(jira_usage, jira_import_usage)
         # rubocop: enable UsageData/LargeTable:
       end

spec/lib/gitlab/usage_data_spec.rb

@@ -344,6 +344,8 @@ RSpec.describe Gitlab::UsageData, :aggregate_failures do
       expect(count_data[:projects_slack_slash_commands_active]).to eq(1)
       expect(count_data[:projects_custom_issue_tracker_active]).to eq(1)
       expect(count_data[:projects_mattermost_active]).to eq(0)
+      expect(count_data[:templates_mattermost_active]).to eq(1)
+      expect(count_data[:instances_mattermost_active]).to eq(1)
       expect(count_data[:projects_with_repositories_enabled]).to eq(3)
       expect(count_data[:projects_with_error_tracking_enabled]).to eq(1)
       expect(count_data[:projects_with_alerts_service_enabled]).to eq(1)