[Merge] ~rbalint/livecd-rootfs:ubuntu/master into livecd-rootfs:ubuntu/master

[Balint Reczey]

I added the new script to debian/install and tests are passing this way:

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal-rbalint-scratch/focal/amd64/l/livecd-rootfs/20191113_193920_ad5fd@/log.gz

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https://code.launchpad.net/~rbalint/livecd-rootfs/+git/livecd-rootfs/+merge/375450
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~rbalint/livecd-rootfs:ubuntu/master into livecd-rootfs:ubuntu/master.