artifact windows-ubuntu fails but report success

created a Windows VM with this artifact [windows-ubuntu](https://github.com/Azure/azure-devtestlab/blob/c741a6703fef9a99a160901bd45bda17cc3fb066/Artifacts/windows-ubuntu/Artifactfile.json). When the machine was created, the execution reported succesful execution:

`````
Artifact Information
Artifact
Name
Windows Ubuntu
Repository
Public Artifact Repo
Status
Succeeded
Install Time
Wed May 13 2020 21:20:05 GMT-0700 (Pacific Daylight Time)
`````

Nevertheless, **it failed**. This is the output of the artifact:

````
Creating Ubuntu Distro Folder
Downloading Ubuntu Distro
Renaming .appx to .zip
Unzipping Distro
Installing Ubuntu
Microsoft Windows [Version 10.0.18363.836]
(c) 2019 Microsoft Corporation. All rights reserved.

C:\Distros>C:\Distros\Ubuntu\ubuntu1804.exe install --root
Installing, this may take a few minutes...

WslRegisterDistribution failed with error: 0x8007019e

The Windows Subsystem for Linux optional component is not enabled. Please enable it and try again.

See https://aka.ms/wslinstall for details.
````

Start with Artifacts/windows-ubuntu/Artifactfile.json and reproduce the artifact on a Windows VM where the Windows Subsystem for Linux component is disabled. Trace how the `ubuntu1804.exe install --root` result is handled and make the reported artifact status match the failed installation, then verify the failure output is surfaced.

索引モデルが issue の本文から書いたものです。