This change replaces the call to grub2-switch-to-blscfg with a file
rename to update it to the actual machine-id.
grub2-switch-to-blscfg has issues in some build environments:
- When the build host is EFI boot, it assumes the image is, and
fails when config file /etc/grub2-efi.cfg is missing
- With recent cento9 images and a fedora build host it fails with:
grub2-probe: error: cannot find a device for / (is /dev mounted?)
Change-Id: I74ad800b702f2b491d958555cef8d7c7f63d74ac
0d0f7f8075