adtrust upgrade: fix wrong primary principal name
Upgrade code had Kerberos principal names mixed up: instead of creating
krbtgt/LOCAL-FLAT@REMOTE and marking LOCAL-FLAT$@REMOTE as an alias to
it, it created LOCAL-FLAT$@REMOTE Kerberos principal and marked
krbtgt/LOCAL-FLAT@REMOTE as an alias.
This differs from what Active Directory expects and what is created by
ipasam plugin when trust is established. When upgrading such deployment,
an upgrade code then unexpectedly failed.
Reviewed-By: Rob Crittenden <email@example.com>