iso image creation fails for rhel7 image

[Anshul Jain]

iso/post-install.d/01-copy-bootloaders: Current behavior does not have support to build rhel iso image.
It tries to copy bootloaders as defined by ubuntu based images which does not work for RHEL.

RHEL bootloaders can be found at /boot/efi/EFI/redhat/ path, while script looks for them in "/usr/lib"

Element "iso" requires update in path for GRUB_FILE, SHIM_FILE and SYSLINUX_FILE to build rhel7 iso image.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/548585

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/548585
Committed: https://git.openstack.org/cgit/openstack/diskimage-builder/commit/?id=73a9ba0f1fcf43bcd2ee6e685fbcc2828814f5e8
Submitter: Zuul
Branch: master

commit 73a9ba0f1fcf43bcd2ee6e685fbcc2828814f5e8
Author: Anshul Jain <email address hidden>
Date: Wed Feb 28 06:31:34 2018 -0600

    Fix for rhel7 iso image creation.

    Currently rhel7 image creation fails because it tries to copy
    default bootloaders which is ubuntu way. This commit updates `iso`
    element to correct the path of bootloaders required for rhel image.

    Change-Id: I526d75b2db609fc77be0fc778b4d00f2d3df38ec
    Closes-bug: 1750725