Add expand:instanceView for GET VMScaleSetVM

**Resource Provider**
What is the Azure resource provider your feature is part of?
Microsoft.Compute

**Description of Feature or Work Requested**
Provide a brief description of the feature or work requested. A link to conceptual documentation may be helpful too.

GET for VMScaleSet VM has added an expand parameter to the swagger spec to display the instance view.

**Minimum API Version Required**
What is the minimum API version of your service required to implement your feature?

**Swagger Link**
Provide a link to the location of your feature(s) in the REST API specs repo. This should be on the master branch
of the REST API specs repo.

https://github.com/Azure/azure-rest-api-specs/blob/master/specification/compute/resource-manager/Microsoft.Compute/stable/2019-03-01/compute.json

"operationId": "VirtualMachineScaleSetVMs_Get",
"name": "$expand",
"enum": [
"instanceView"

line 4688

**Target Date**
If you have a target date for release of this feature/work, please provide it. While we can't guarantee these dates,
it will help us prioritize your request against other requests.
8/31/2019