selinux-autorelabel service can be configured to drop to a shell to allow
administrator to manually relabel a filesystem, see selinux_config(5). In
this case, the service needs to have a tty attached to stdin. Given that
tty should not be attached to the service by default, see
https://bugzilla.redhat.com/show_bug.cgi?id=1634661 , the
selinux-autorelabel-generator.sh will configure the service to attach
tty only if AUTORELABEL=0
Resolves: rhbz#2165508