leapp fails with "Found GRUB devices with too little space reserved before the first partition" or "Actor scan_grub_device_partition_layout unexpectedly terminated with exit code: 1"

Issue

• leapp preupgrade fails with inhibitor

  Risk Factor: high (inhibitor)
  Title: Found GRUB devices with too little space reserved before the first partition
  Summary: On the system booting by using BIOS, the in-place upgrade fails when upgrading the GRUB2 bootloader if the boot disk's embedding area does not contain enough space for the core image installation. This results in a broken system, and can occur when the disk has been partitioned manually, for example using the RHEL 6 fdisk utility.
  
  The list of devices with small embedding area:
  - /dev/sda.
  Remediation: [hint] We recommend to perform a fresh installation of the RHEL 8 system instead of performing the in-place upgrade.
  Another possibility is to reformat the devices so that there is at least 1024 kiB space before the first partition. Note that this operation is not supported and does not have to be always possible.
  

• Alternatively leapp preupgrade fails in error

  Risk Factor: high (error)
  Title: Actor scan_grub_device_partition_layout unexpectedly terminated with exit code: 1
  Summary: Traceback (most recent call last):
    File "/usr/lib/python2.7/site-packages/leapp/repository/actor_definition.py", line 74, in _do_run
      actor_instance.run(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/leapp/actors/__init__.py", line 289, in run
      self.process(*args)
    File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/actors/scangrubdevpartitionlayout/actor.py", line 18, in process
      scan_layout_lib.scan_grub_device_partition_layout()
    File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/actors/scangrubdevpartitionlayout/libraries/scan_layout.py", line 89, in scan_grub_device_partition_layout
      dev_info = get_partition_layout(device)
    File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/actors/scangrubdevpartitionlayout/libraries/scan_layout.py", line 76, in get_partition_layout
      part_device = part_info[0]
  IndexError: list index out of range