Fluent: would like to create/referencing NetworkSecurityGroup in VMSS definition API

_From @TimLovellSmith on September 7, 2017 20:27_

With 1.1.3 I can't see any way to define the 'networkSecurityGroup' field for the VMSS network interface configuration part of the REST API!

From what I've seen of 1.2.0 release notes I am guessing that this functionality isn't yet added there either?

(This is what I'm talking about:

"networkProfile": {
"networkInterfaceConfigurations": [ {
"name": "nicconfig1",
"properties": {
"primary": true,
"enableAcceleratedNetworking": false,
"networkSecurityGroup": {
"id": "/subscriptions/{subscription-id}/resourceGroups/myrg1/providers/Microsoft.Network/networkSecurityGroups/nsg1"
},

I have heard that using this mechanism is functionally slightly different from just applying an NSG on your subnet, it gets applied on the NICS instead, hence the desire for it. Haven't been able to test it out yet though...)

_Copied from original issue: Azure/azure-sdk-for-net#3672_

Start by locating the Java VMSS definition API and comparing its network interface configuration model with the REST example in the issue. Determine where networkSecurityGroup support would belong and verify the resulting definition can represent the requested NSG association. Done means the API exposes this configuration and has coverage for the VMSS network profile behavior.

Written by the indexing model from the issue text.