Templates using Secure parameters are missing the rendered placeholder value

[ms-sambell]

Description of the issue

When rendering a template that uses a secure parameter the PSRule engine should convert the secureString parameter into a placeholder value. This isn't happening right now, the value is being added in clear text.

To Reproduce

Steps to reproduce the issue:

1. Export the tests for a template that uses secure parameters.
2. Check the output directory.
3. Check the secureParameter to see if it's been overridden with the placeholder.

Expected behavior

The variable should be set with a default value.

Module in use and version:

• Module: PSRule.Rules.Azure 1.18.0

Captured output from $PSVersionTable:

Name                           Value
----                           -----
PSVersion                      7.3.0-preview.6
PSEdition                      Core
GitCommitId                    7.3.0-preview.6
OS                             Microsoft Windows 10.0.22000
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0