GitLab: backfill service from template

gitlab-backfill-service-from-template.rb

service_klass_to_property_keys = {
  JiraService => %w[api_url url username password]
}

service_klass_to_property_keys.each do |klass, property_keys|
  template_properties = klass.find_by!(template: true).properties.slice(*property_keys)

  klass.find_each do |service|
    service.properties = service.properties.merge(template_properties)
    service.save! if service.changed?
  end
end