Add Rails command for enabling cleanup policy on older projects

doc/user/packages/container_registry/index.md

@@ -512,6 +512,11 @@ Cleanup policies can be run on all projects, with these exceptions:
   for all projects (even those created before 12.8) in
   [GitLab application settings](../../../api/settings.md#change-application-settings)
   by setting `container_expiration_policies_enable_historic_entries` to true.
+  Alternatively, you can execute the following command in the [Rails console](../../../administration/troubleshooting/navigating_gitlab_via_rails_console.md#starting-a-rails-console-session):
+
+  ```ruby
+  ApplicationSetting.last.update(container_expiration_policies_enable_historic_entries: true)
+  ```
 
   There are performance risks with enabling it for all projects, especially if you
   are using an [external registry](./index.md#use-with-external-container-registries).