Fix PS deploy code for App Attach Tools VM Issue #674

[JCoreMS]

Overview/Summary

Fix PS code for deployment of App Attach Tools VM

This PR fixes/adds/changes/removes

1. Fix for issue Powershell Deployement Error in https://github.com/Azure/avdaccelerator/blob/main/workload/bicep/brownfield/appAttachToolsVM/Readme.md #674

Breaking Changes

1. N/A

Testing Evidence

Replace this with any testing evidence to show that your Pull Request works/fixes as described and planned (include screenshots, if appropriate).

As part of this Pull Request I have

• Read the Contribution Guide and ensured this PR is compliant with the guide
• Ensured the resource API versions in .bicep file/s I am adding/editing are using the latest API version possible
• Checked for duplicate Pull Requests
• Associated it with relevant GitHub Issues
• (AVD LZA Team Only) Associated it with relevant ADO Items
• Ensured my code/branch is up-to-date with the latest changes in the main branch
• Performed testing and provided evidence.
• Updated relevant and associated documentation (e.g. Contribution Guide, Module READMEs, Docs etc.)