Currently, skip_grub_config and initrd_remove_dir options in the
bootloader plug-in are inconsistent. This commit fixes this issue.
The skip_grub_config=VALUE does not change grub configuration if VALUE
is true. However, cmdline options are still processed, and the result
is used to verify the current cmdline. Only 'y', 'yes', 't', 'true' and
'1' (case insensitive) are accepted as true values for this option.
Other values are interpreted as false.
Example:
[bootloader]
skip_grub_config=True
cmdline=+systemd.cpu_affinity=1
Signed-off-by: Jiri Mencak <jmencak@users.noreply.github.com>