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_