Resource iteration in ADF ARM templates for DataLakeAnalyticsScope

Question

I am trying to create an ADF template to deploy a pipeline which will create N DataLakeAnalyticsScope activity based on parameters.

for example the parameters will look like this. In the parameters I have array of scope activity. I want to create multiple scope activities based on number of elements supplied in the array

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "factoryName": {
      "value": "factoryName"
    },
    "adls_ls": { "value": "adls_ls" },
    "adla_ls": { "value": "adla_ls" },
    "scopeActivities": {
      "value": [
        {
          "scriptFolder": "folder1",
          "scriptFile": "file1"
        },
        {
          "scriptFolder": "folder2",
          "scriptFile": "file2"
        }      
      ]
    }
  }
}

The option I found is, to use resource iterator as per this article

As per the article, my arm template should look something like this

{
  "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "factoryName": {
      "type": "string",
      "metadata": "Data Factory name"
    },
    "adls_ls": { "type": "string" },
    "adla_ls": { "type": "string" },
    "scopeActivities": {
      "type": "array"
    },
    "scriptFolderPath": {
      "type": "string"
    },
    "scriptFileName": {
      "type": "string"
    }
  },
  "variables": {
    "factoryId": "[concat('Microsoft.DataFactory/factories/', parameters('factoryName'))]",
    "pipelineName": "POCPipeline"
  },
  "resources": [
    {
      "name": "[concat(parameters('factoryName'), '/', variables('pipelineName'))]",
      "type": "Microsoft.DataFactory/factories/pipelines",
      "apiVersion": "2018-06-01",
      "properties": {
        "activities": [
          //other activities
        ]
      }
    },
    {
      "name": "[concat(parameters('factoryName'), '/', variables('pipelineName'))],'/',[concat('Scope Activity ',parameters('scopeActivities')[copyIndex()]))]",
      "type": "Microsoft.DataFactory/factories/pipelines/DataLakeAnalyticsScope",
      "dependsOn": [
        "[concat(parameters('factoryName'), '/', variables('pipelineName'))]"
      ],
      "policy": {
        "timeout": "0.12:00:00",
        "retry": 0,
        "retryIntervalInSeconds": 30,
        "secureOutput": false,
        "secureInput": false
      },
      "userProperties": [],
      "typeProperties": {
        "scriptFolderPath": "[parameters('scopeActivities')[copyIndex()].scriptFolder]",
        "scriptFileName": "parameters('scopeActivities')[copyIndex()].scriptFile",
        "scriptLinkedService": {
          "referenceName": "[parameters('adls_ls')]",
          "type": "LinkedServiceReference"
        }
      },
      "linkedServiceName": {
        "referenceName": "[parameters('adls_ls')]",
        "type": "LinkedServiceReference"
      },
      "copy": {
        "name": "blobcopy",
        "count": "[length(parameters('scopeActivities'))]"
      }
    }
  ]
}

But I get this error

New-AzResourceGroupDeployment : 6:19:39 PM - Error: Code=InvalidRequestContent; Message=The request content was invalid and could not be deserialized: 'Could not find member 'policy' on object of type 'TemplateResource'. Path 'properties.template.resources[1].policy', line 72,
position 19.'

I dont know what is wrong with the above template. Can someone please help

Thanks