Ubuntu 20.04 "A stop job is running for Snappy Daemon" during shutdown

[JP Meijers]

When restarting my computer the shutdown process will hang for a 1m30s timeout period on the line reading "A stop job is running for Snappy Daemon".

Fully updated Ubuntu 20.04 install. Almost fresh install with minimal software loaded.

```
$ snap list
Name Version Rev Tracking Publisher Notes
arduino 1.8.12 14 latest/edge merlijn-sebrechts -
canonical-livepatch 9.5.5 95 latest/stable canonical✓ -
core 16-2.44.3 9066 latest/stable canonical✓ core
core18 20200311 1705 latest/stable canonical✓ base
gnome-3-34-1804 0+git.2c86692 27 latest/stable/… canonical✓ -
goland 2020.1 86 latest/stable jetbrains✓ classic
google-cloud-sdk 290.0.1 129 latest/stable google-cloud-sdk✓ classic
gtk-common-themes 0.1-36-gc75f853 1506 latest/stable/… canonical✓ -
gtk2-common-themes 0.1 9 latest/stable canonical✓ -
pycharm-professional 2020.1 196 latest/stable jetbrains✓ classic
skype 8.59.0.77 123 latest/stable skype✓ classic
snap-store 3.36.0-74-ga164ec9 433 latest/stable/… canonical✓ -
snapd 2.44.3 7264 latest/stable canonical✓ snapd
```

Also mentioned:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911906
http://ubuntuhandbook.org/index.php/2019/12/slow-shutdown-stop-job-running/