If the GRUB install device has not been selected, then grub package
configuration will fail during upgrades.
Tests:
- Install freedombox package with this change in a VM. Check that the
diagnostic is passed.
- Re-install the grub-pc package with DEBIAN_FRONTEND set to
noninteractive, so that it fails to be configured. Check that the
diagnostic is failed.
Signed-off-by: James Valleroy <jvalleroy@mailbox.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>