Boolean string conversion case

[BernieWhite]

Description of the issue

When a bool is converted to a string the default .NET type converter has a different behaviour than ARM.

For example:

• ARM: string(true()) = True, string(false()) = False
• .NET: true = true, false = false.

To Reproduce

Steps to reproduce the issue:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-08-01/tenantDeploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "variables": {
        "lookup": {
            "True": {
                "value": "True"
            },
            "true": {
                "value": "true"
            },
            "false": {
                "value": "false"
            }
        }
    },
    "resources": [
        {
            "type": "Namespace/resourceType",
            "apiVersion": "2020-05-01",
            "name": "resource",
            "location": "region",
            "properties": {
                "value1": "[variables('lookup')[string(empty(''))].value]",
                "value2": "[variables('lookup')[tolower(string(empty('')))].value]",
                "value3": "[variables('lookup')[string(not(empty('')))].value]"
            }
        }
    ]
}

Expected behaviour

Update string() function to use True and False for converted bool value instead of true and false.

Module in use and version:

• Module: PSRule.Rules.Azure
• Version: 1.4.0

Captured output from $PSVersionTable:

Name                           Value
----                           -----
PSVersion                      7.1.3
PSEdition                      Core
GitCommitId                    7.1.3
OS                             Microsoft Windows 10.0.19043
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0