fix(arm): use correct type casting for ints in azure scan

[nikpivkin]

The wrong type was used when converting the value to int.

See aquasecurity/trivy#4792

Example to reproduce the problem:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "2.0.0.0",
    "apiProfile": "2019-03-01-hybrid",
    "parameters": {},
    "variables": {},
    "functions": [],
    "resources": [
        {
            "name": "flowlogs/sample",
            "type": "Microsoft.Network/networkWatchers/flowLogs",
            "apiVersion": "2020-11-01",
            "location": "location",
            "tags": {},
            "properties": {
                "targetResourceId": "targetResourceId",
                "storageId": "storageId",
                "enabled": true,
                "retentionPolicy": {
                    "days": 2
                },
                "format": {
                    "type": "JSON"
                }
            }
        }
    ],
    "outputs": {}
}

[simar7]

nice, could you add a test for it?