Optimize service usage counters in usage data

Enable batch counting and eliminate group by

changelogs/unreleased/210007-optimize-services_usage-counters.yml

+---
+title: Optimize services usage counters using batch counters
+merge_request: 26973
+author:
+type: performance

lib/gitlab/usage_data.rb

@@ -183,10 +183,8 @@ module Gitlab
 
       # rubocop: disable CodeReuse/ActiveRecord
       def services_usage
-        service_counts = count(Service.active.where(template: false).where.not(type: 'JiraService').group(:type), fallback: Hash.new(-1), batch: false)
-
-        results = Service.available_services_names.each_with_object({}) do |service_name, response|
-          response["projects_#{service_name}_active".to_sym] = service_counts["#{service_name}_service".camelize] || 0
+        results = Service.available_services_names.without('jira').each_with_object({}) do |service_name, response|
+          response["projects_#{service_name}_active".to_sym] = count(Service.active.where(template: false, type: "#{service_name}_service".camelize))
         end
 
         # Keep old Slack keys for backward compatibility, https://gitlab.com/gitlab-data/analytics/issues/3241