[Pkg-rust-maintainers] Bug#1089203: systemd-zram-generator: Removes user configuration on every update

[cacin at allfreemail.net]

Package: systemd-zram-generator
Followup-For: Bug #1089203

The manpage for zram-generator.conf lists the following configuration
files:

```
/usr/lib/systemd/zram-generator.conf
/usr/local/lib/systemd/zram-generator.conf
/etc/systemd/zram-generator.conf
/run/systemd/zram-generator.conf

/usr/lib/systemd/zram-generator.conf.d/*.conf
/usr/local/lib/systemd/zram-generator.conf.d/*.conf
/etc/systemd/zram-generator.conf.d/*.conf
/run/systemd/zram-generator.conf.d/*.conf
```

In debian bookworm, the default configuration file for
systemd-zram-generator was incorrectly placed in
/etc/systemd/zram-generator.conf. This is not ideal, as any
modifications made by the local system administrator could be lost
during package upgrades, and dpkg may generate warnings.

The debian package has since been updated to correctly place the default
configuration at the /usr/lib/systemd/zram-generator.conf location.
System administrators should ideally make configuration changes by
creating snippets in the /etc/systemd/zram-generator.conf.d/ directory.

This approach works in both debian bookworm and debian trixie.

Hence, to avoid potential issues, ideally use configuration files such
as /etc/systemd/zram-generator.conf.d/zram0.conf and
/etc/systemd/zram-generator.conf.d/zram1.conf

These files will not be lost nor overwritten during package upgrades.

For further details, refer to the specifications at [1]

[1] https://uapi-group.org/specifications/specs/configuration_files_specification/