incremental upgrades: do not try to update media unless created using the Tails USB installer

Should not try to update a Tails that was not created using Tails USB installer

Tails::Persistence::Setup has code to check if the system was created using the Tails USB installer (device_has_tails). It should not be too hard to reuse it.

Parent Task: #5922 (closed)

Original created by @tails on 5321 (Redmine)

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