Use ACI class set_permissions() method to set permissions
This will ensure uniqueuess and that the ACI has the right
datatype without the caller worrying about it.
https://pagure.io/freeipa/issue/8443
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>