Confirm that Briar Desktop is shutting down like Android

Briar Android's shutdown is handled in `BriarService::onDestroy`

and `BriaService::shutdownFromBackground`

There, there are some more Android specific stuff like wakelocks,
`stopForeground()` and `unregisterReceiver()` calls, but in general it
does the same like Desktop: call `stopServices()` and then

As part of this TODO search, I created the following issues and
comments between those two chat logs:

Besides this single TODO I found no other TODO comment either important
enough to create a new issue or comment or eligible to get removed.

Fixes #140
1 job for !113 with 140-todo in 4 minutes and 56 seconds (queued for 6 seconds)
latest merge request