Issue Summary

Confluence system apps are installed by anonymous users.
When Confluence installs a system app, in the audit trail it shows the user name as `anonymous`. Ideally, it should be something that tells the customers that it was done by

Steps to Reproduce

1. As an admin, Go to UPM audit logs https://your-instance.atlassian.com/wiki/plugins/servlet/upm/log?source=manage
2. Look at auto updates / installs

Expected Results

Auto updates / installs should show as done by Atlassian.

Actual Results

Auto updates / installs show as done by `anonymous` user.

Workaround

None