Gitlab-shell error during backup restore

Affected: 6.8 EE packages, 6.9 CE, 6.9 EE.

This will rebuild an authorized_keys file.
You will lose any data stored in authorized_keys file.
Do you want to continue (yes/no)? yes

/opt/gitlab/embedded/service/gitlab-shell/lib/gitlab_keys.rb:84:in `initialize': Permission denied - /opt/gitlab/embedded/service/gitlab-shell/authorized_keys.lock (Errno::EACCES)
        from /opt/gitlab/embedded/service/gitlab-shell/lib/gitlab_keys.rb:84:in `open'
        from /opt/gitlab/embedded/service/gitlab-shell/lib/gitlab_keys.rb:84:in `lock'
        from /opt/gitlab/embedded/service/gitlab-shell/lib/gitlab_keys.rb:39:in `batch_add_keys'
        from /opt/gitlab/embedded/service/gitlab-shell/lib/gitlab_keys.rb:19:in `exec'
        from /opt/gitlab/embedded/service/gitlab-shell//bin/gitlab-keys:25:in `<main>'
Failed to add keys...

Workaround:

sudo touch /opt/gitlab/embedded/service/gitlab-shell/authorized_keys.lock
sudo chown git /opt/gitlab/embedded/service/gitlab-shell/authorized_keys.lock