This explicitly sets the systemd default.target symlink to point to
graphical.target.
This also fixes a previous bug with the "-e" file check that always
returned false even if default.target existed since it was being run
from outside the chroot. This would result in the container booting into
multi-user.target (set by LXC during lxc-create), not starting up the
display manager, and resulting in blank HDMI display output.
This explicitly sets the systemd default.target symlink to point to graphical.target.
This also fixes a previous bug with the "-e" file check that always returned false even if default.target existed since it was being run from outside the chroot. This would result in the container booting into multi-user.target (set by LXC during lxc-create), not starting up the display manager, and resulting in blank HDMI display output.