Imported using git-ubuntu import.
Changelog parent: 71b98bc5dfbd93634097a46c56672528481fbf2a
New changelog entries:
* In subiquity image, mount additional squashfs in /media.
* Make lzma initramfs compression opt-in rather than opt-out, and do not
opt-in to it for live-server builds to speed up the boot. (LP: #1750873)
