Azure Installation issue -- fail to load bootstrap ignition config when using an uploaded custom OS IMAGE OVERRIDE

[japecci]

The installers from 4.12 to 4.17scos for okd all experience the same issue.

When trying to set up the cluster you get the following error:
FATAL failed to fetch Bootstrap Ignition Config: failed to fetch dependency of "Bootstrap Ignition Config": failed to fetch dependency of "Worker Machines": failed to generate asset "Release": stable/x86_64: No azure build found

I've seen the discussions on several issues related and seemed to fix with uploading the FCOS image to azure and using the env variable to override which I've done : setting this one OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE.

For installer 4.11 it works. 4.12 to 4.17scos even though the override is present with the corresponding FCOS image it does not work.

Seems related to this:
#4986

some validation failing because fcos.json does not set :
"rhel-coreos-extensions": {
"azure-disk": {
"release": "34.20210626.3.10",
"url": "https://[yourstorageaccount].blob.core.windows.net/fcos/fcos.vhd"
}
}