After upgrading from RHEL6, grub2-install commands fails with message "error: will not proceed with blocklists"

Issue

• After upgrading the system from RHEL6 to RHEL7 using redhat-upgrade-tool tool, it's not possible to replace the Grub bootloader with Grub2 due to getting the following error message

  # grub2-install /dev/sda
  Installing for i386-pc platform.
  grub2-install: warning: your embedding area is unusually small.  core.img won't fit in it..
  grub2-install: warning: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and their use is discouraged..
  grub2-install: error: will not proceed with blocklists.