Users receiving storage not found errors

Steps to reproduce:

1. Export a project on GitLab.com
2. Import a project

This suggests whichever nodes are handling the import don't have the right Gitaly configuration.

Related issues:

• https://gitlab.com/gitlab-com/support-forum/issues/4239
• https://gitlab.com/gitlab-org/gitlab-ce/issues/46646#note_129093784