Field identity is ignored for the resource type Microsoft.Web/sites

Hello,

if you create an Azure function or an App Service without Managed Identity and you launch the ARM Template what if to create it, you won't be prompt to enable it.

Sample code
`
{
"type": "Microsoft.Web/sites",
"apiVersion": "2019-08-01",
"name": "[parameters('appName')]",
"location": "[parameters('location')]",
"tags": "[union(variables('additional_tags'),resourceGroup().tags)]",
"kind": "[parameters('appKind')]",
"identity": {
"type": "SystemAssigned"
},
"properties": {
"serverFarmId": "[concat(main.getResource('Microsoft.Web/serverfarms',parameters('hostingPlanSubscriptionId'), parameters('hostingPlanResourceGroupName'),parameters('hostingPlanName')).id)]",
"siteConfig": {
"appSettings": "[variables('appSettings')]",
"http20Enabled": true,
"localMySqlEnabled": false,
"netFrameworkVersion": "v4.0",
"use32BitWorkerProcess": "false",
"scmType": "VSTSRM",
"alwaysOn": "[parameters('alwaysOn')]",
"cors": "[if(equals(length(parameters('allowedOrigins')),0), json('null'),variables('cors'))]"
},
"clientAffinityEnabled": "false"
},
`

Sample result

Regards,
James

Start with the Microsoft.Web/sites ARM template in the issue and reproduce the what-if result for an Azure Function or App Service with the shown SystemAssigned identity and without Managed Identity. Trace how the what-if output handles the identity field, then verify that the result prompts to enable the identity when appropriate.

Written by the indexing model from the issue text.