[Merge] ~sdeziel/ubuntu/+source/lxd-installer:lxd-next-lts into ubuntu/+source/lxd-installer:ubuntu/devel

[Simon Déziel]

`autopkgtest -U -s ../lxd-installer_4_source.changes -- lxd ubuntu-minimal-daily:20.04`
```
autopkgtest [22:02:09]: test install-on-demand: [-----------------------
+ . /etc/os-release
+ NAME=Ubuntu
+ VERSION=20.04.6 LTS (Focal Fossa)
+ ID=ubuntu
+ ID_LIKE=debian
+ PRETTY_NAME=Ubuntu 20.04.6 LTS
+ VERSION_ID=20.04
+ HOME_URL=https://www.ubuntu.com/
+ SUPPORT_URL=https://help.ubuntu.com/
+ BUG_REPORT_URL=https://bugs.launchpad.net/ubuntu/
+ PRIVACY_POLICY_URL=https://www.ubuntu.com/legal/terms-and-policies/privacy-policy
+ VERSION_CODENAME=focal
+ UBUNTU_CODENAME=focal
+ echo Executing test on Ubuntu version 20.04
+ echo Check which lxd-installer version we have installed
+ dpkg -l
+ grep -wF lxd-installer
Executing test on Ubuntu version 20.04
Check which lxd-installer version we have installed
ii  lxd-installer                  4                                 all          Wrapper to install lxd snap on demand
Make sure LXD's snap is not seeded in the current image
+ echo Make sure LXD's snap is not seeded in the current image
+ snap list lxd
error: no matching snaps installed
+ echo Report list of installed snaps:
+ snap list
Report list of installed snaps:
No snaps are installed yet. Try 'snap install hello-world'.
+ echo Trigger the on-demand installation
+ lxc list
Trigger the on-demand installation
Installing LXD snap, please be patient.
+ echo Check which version of LXD was installed
+ snap list lxd
Check which version of LXD was installed
Name  Version        Rev    Tracking      Publisher    Notes
lxd   4.0.9-a29c6f1  24061  4.0/stable/…  canonical**  -
+ snap info lxd
+ awk /^tracking: / {print $2}
+ TRACKING=4.0/stable/ubuntu-20.04
+ [ 20.04 = 24.04 ]
+ [ 20.04 = 22.04 ]
+ [ 20.04 = 20.04 ]
+ EXPECTS=4.0/stable/ubuntu-20.04
+ echo Verify it matches the expected version
+ [ 4.0/stable/ubuntu-20.04 = 4.0/stable/ubuntu-20.04 ]
+ echo lxd-installer installed LXD from the right track (4.0/stable/ubuntu-20.04)
Verify it matches the expected version
lxd-installer installed LXD from the right track (4.0/stable/ubuntu-20.04)
autopkgtest [22:03:26]: test install-on-demand: -----------------------]
autopkgtest [22:03:26]: test install-on-demand:  - - - - - - - - - - results - - - - - - - - - -
install-on-demand    PASS
autopkgtest [22:03:26]: @@@@@@@@@@@@@@@@@@@@ summary
install-on-demand    PASS
```
-- 
https://code.launchpad.net/~sdeziel/ubuntu/+source/lxd-installer/+git/lxd-installer/+merge/459613
Your team Ubuntu Sponsors is requested to review the proposed merge of ~sdeziel/ubuntu/+source/lxd-installer:lxd-next-lts into ubuntu/+source/lxd-installer:ubuntu/devel.