Add nuget package to get the .NET SDK

Now that a nuget package is out for the .NET SDK, this
change adds the ability to get it in the same manner
as the other SDKs.

Closes-Bug: #1325035
Change-Id: I75d77d0ae00c76378391faca4e418c2b4f008296
Merge "Add nuget package to get the .NET SDK"