Comment 1 for bug 1418966

My theory for this is behavior is:
- /etc/hostname is a overlay in /writable/system-data/etc/writable/hostname
- on boot our initramfs hook prepares the /etc/fstab that contains the mount for /etc/hostname but does not mount it (this is for systemd) so /etc/hostname contains "localhost"
- when systemd runs it calls hostname_setup() in main.c:1563, the olverlay is not mounted yet so it uses the old "localhost"
- and then runs into its main loop where it executes the units to mount the overlay