The test was originally introduced for Ubuntu CI, as it uses
PREFER_NSPAWN=1, but it was subsequently disabled two years ago [0], so
it was pretty much useless. Let's merge it into TEST-02 and tweak it a
bit to run only certain tests under QEMU when $TEST_PREFER_NSPAWN is
set.
[0] b152adbfa9
The kernel command line may contain newlines which kernel happily
accepts, but we'd ignore everything past the first newline. Let's fix
that by replacing read_one_line_file() with read_full_file().
ImportCredential= takes a credential name and searches for a matching
credential in all the credential stores we know about it. It supports
globs which are expanded so that all matching credentials are loaded.
With these settings we intend to turn off timeouts for possibly
interactive/slow commands. The officially documented way to turn off the
time-outs is to setting them to infinity. So far we set them to zero
here though.
This lead to some confusiong, for example #18224. Let's fix this by
uniformly spelling out TimeoutSec=infinity.
This doesn't change behaviour. It just makes our generated files match
what we document, without relying on historic compat support.
Fixes: #18224
Turns out we can, apart from just building the module, "shove" it into
the SELinux database in a chroot as well. This brings quite significant
time savings, as the SELinux db rebuild takes 2 - 5 minutes in a VM
without acceleration (and takes currently ~half of the runtime of the test
in the C8S job).
