windows-startup-script-url: Message: Either the Name or Index parameter is required

I'm following the steps here: https://cloud.google.com/compute/docs/images/creating-custom-windows-byol-images#building

and my cloud build steps are failing because I'm not passing in $edition.

But it's able to print it out in the line before: https://github.com/GoogleCloudPlatform/compute-image-tools/blob/master/daisy_workflows/image_build/windows/bootstrap_install.ps1#L203

Here is here my cloud build fails
```
023/07/07 18:05:13 GCEMetadataScripts: windows-startup-script-url: Formatting UEFI install disk complete.
2023/07/07 18:05:13 GCEMetadataScripts: windows-startup-script-url: Retrieved metadata for key edition with value Windows10Enterprise.
2023/07/07 18:05:13 GCEMetadataScripts: windows-startup-script-url: Applying Windows10Enterprise wim image to install disk.
2023/07/07 18:05:15 GCEMetadataScripts: windows-startup-script-url: ISO mounted as E
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: Exception caught in script:
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: At C:\Windows\TEMP\metadata-scripts3214937362\windows-startup-script-url.ps1:204 char:3
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: + Expand-WindowsImage -ImagePath $(Get-Wim) -Name $edition -ApplyPath ...
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: Message: Either the Name or Index parameter is required
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url: Windows build failed.
2023/07/07 18:05:16 GCEMetadataScripts: windows-startup-script-url exit status 1
2023/07/07 18:05:16 GCEMetadataScripts: Finished running startup scripts.
2023/07/07 18:05:26 GCEMetadataScripts: Starting shutdown scripts (version 20230403.00).
2023/07/07 18:05:26 GCEMetadataScripts: No shutdown scripts to run.
2023-07-07T18:2023/07/07 18:05:26 GCEGuestAgent: GCE Agent Stopped
```