Autologin for existing user disabled after ISO build in Backup mode, Ubuntu 18.04

[kamwoods]

When creating an ISO in Backup mode for the current user in stock Ubuntu 18.04, autologin for that user (if set) is disabled after installing from that ISO (that is, you get dropped to the login screen on first boot after install). This behavior is not specific to PinguyBuilder alone - it appears other remastersys-derived builders (Bodhibuilder, etc) exhibit this behavior as well since Ubuntu switched to GNOME.

It seems like autologin should be retained if set particularly since stock Ubuntu allows you to set it during install, as well.