additionalUnattendContent FirstLogonCommands example

Hi, could someone provide a working example of a VM using additionalUnattendContent.
For some reason I'm unable to get the FirstLogonCommands working. Always receive an error:
'The value of parameter windowsConfiguration.additionalUnattendContent.content is invalid.'

```
"additionalUnattendContent": [
{
"passName": "oobeSystem",
"componentName": "Microsoft-Windows-Shell-Setup",
"settingName": "FirstLogonCommands",
"content": "powershell1"
}
```

Also tried to base-64 encode the content string. Same error.

[additionalUnattendContent](https://msdn.microsoft.com/nl-nl/library/azure/mt163591.aspx#bk_addcontent)

> - pass
> Specifies the name of the pass that the content applies to. The only allowable value is oobeSystem.
> - component
> Specifies the name of the component to configure with the added content. The only allowable value is Microsoft-Windows-Shell-Setup.
> - settingName
> Specifies the name of the setting to which the content applies. Possible values are: FirstLogonCommands and AutoLogon.
> - content
> Specifies the base-64 encoded XML formatted content that is added to the unattend.xml file for the specified path and component.

Start with the additionalUnattendContent documentation linked in the issue and the Azure VM configuration shown in the report. Verify the required content format for FirstLogonCommands and document a working example that avoids the reported validation error. Done means the example is valid and the issue's requested usage is explained.

Written by the indexing model from the issue text.