If you're uploading a UEFI-enabled VM, the command to update grub is grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg. Also, the vfat kernel module must be enabled in the kernel. Otherwise, provisioning fails.
If you're uploading a UEFI-enabled VM, the command to update grub is grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg. Also, the vfat kernel module must be enabled in the kernel. Otherwise, provisioning fails.