Write regressions tests for updated device list in Tails installer

That is, write automated regression tests for #8691 (closed) and #8353 (closed).

Feature Branch: kytv:test/9131-tails-installer-device-list

Original created by @anonym on 9131 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information