Add registry_prefix to saas module

ee/spec/services/security/security_orchestration_policies/ci_configuration_service_spec.rb

@@ -104,7 +104,7 @@ RSpec.describe Security::SecurityOrchestrationPolicies::CiConfigurationService d
             dependencies: [],
             script: ['gtcs scan'],
             variables: {
-              CS_ANALYZER_IMAGE: 'registry.gitlab.com/security-products/container-scanning:4',
+              CS_ANALYZER_IMAGE: "#{Gitlab::Saas.registry_prefix}/security-products/container-scanning:4",
               GIT_STRATEGY: 'none'
             }
           }

lib/gitlab/saas.rb

@@ -20,6 +20,10 @@ module Gitlab
     def self.dev_url
       'https://dev.gitlab.org'
     end
+
+    def self.registry_prefix
+      'registry.gitlab.com'
+    end
   end
 end