LDAP Directory Test fails with Write operations are not allowed in read-only mode (FlushMode.NEVER): Turn your Session into FlushMode.AUTO or remove 'readOnly' marker from transaction definition

Steps to Reproduce

1. Create a LDAP Directory in Confluence Admin >> User Directories
2. Run the directory test, notice that it will always fail with this:
   

This will happen regardless of which LDAP Permissions are given to the directory (Read Only, Read Only with Local Groups or Read/Write). Not too sure why the authentication test is trying to perform a write operation on the LDAP directory.

Note that a full sync reveals no errors, and users can authenticate normally.