Windows Sandbox backend misreports "not enabled" when wxc-exec runs non-elevated

[brunosonnino]

Relevant area(s)

Windows

Brief description of your issue

Running a windows_sandbox config with a non-elevated wxc-exec.exe fails with "Windows Sandbox is not enabled..." even when the feature is enabled. If you run wxc-exec.exe in an elevated prompt it runs fine. There is no elevation requirement in the documentation.

Steps to reproduce

1. On a host where Windows Sandbox is enabled and dism ... /get-featureinfo shows State : Enabled when run from an elevated prompt.
2. From a non-elevated terminal, run a windows_sandbox config: wxc-exec.exe --experimental windows_sandbox_echo.json (config: { "containment": "windows_sandbox", "process": { "commandLine": "cmd /c echo hi" } })
3. Observe the error.

This error doesn't occur if you run in an elevated prompt

Expected behavior

wxc-exec.exe running non-elevated should correctly detect that Windows Sandbox is enabled and proceed (or, if disabled, say so). Feature-state detection should not require elevation. If elevation is required, it should be documented and the error message should show that.

Actual behavior

Non-elevated wxc-exec.exe reports:
Windows Sandbox is not enabled. Run 'dism /online /enable-feature /featurename:Containers-DisposableClientVM /all' and reboot.
even though the feature is enabled.