[packagekit] Deferred package removal

[Rohan Garg]

Hi Matthias
> Why don't you trigger the removal then when the OEM tool has run after
> the first boot?
> Make the app remove itself when it is run a second time.
> Or, alternatively, you could already implement this logic on top of PK
> using a small tool. I am not sure if this is a useful general feature
> to be shipped with PK...

For the moment I have done just this by writing a systemd unit that
checks for a file that's written out by the OEM tool to /var/lib/ and
removes the tool on reboot. However, I don't really like this solution
since I thought perhaps other distributors might want to do something
similar and will have to write their own systemd units instead of just
calling pkgcon to remove the package on next reboot, which I think is
more consistent behaviour.

FWIW apt also has something like this called apt-mark remove/purge.

Cheers
Rohan Garg