disk-image-create with dhcp-all-interface option does not work for RHEL6 image creation

Issue

• disk-image-create with dhcp-all-interface option does not work for RHEL6 image creation.
• disk-image-create command like disk-image-create rhel baremetal deploy-ironic dhcp-all-interfaces -o rhel6 --mkfs-options "-O ^64bit" succeeds to create an image but the system boot with the image does not reflect dhcp-all-interface option then the system can not be accessed via network.