OpenShift IPI installer uses BIOS instead of UEFI as the boot option on VMware

This is a clone of issue OCPBUGS-9378. The following is the description of the original issue:
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OCP Version at Install Time: 4.11-fc.3
RHCOS Version at Install Time: 411.86.202206172255-0
Platform: vSphere
Architecture: x86_64

I'm trying to verify that the IPI installer uses UEFI when creating VMs on VMware, following https://github.com/coreos/coreos-assembler/pull/2762 (merged Mar 19).

However, the 4.11.0-fc.3 installer taken from https://mirror.openshift.com/pub/openshift-v4/clients/ocp-dev-preview/4.11.0-fc.3/openshift-install-linux.tar.gz still seems to use BIOS.

Reproducing:

1. Run openshift-install against a VMware vSphere cluster.
2. Wait for an OpenShift VM (bootstrap, control, or worker node) to show up in vCenter.
3. Go to the VM's boot options - the firmware is set to BIOS instead of UEFI, which was supposed to be set by default.