Upgrade Cloud Shell VNet Storage Demo

[michaelgira23]

PR Checklist

Check these items before submitting a PR...

Contribution Guide

Best Practice Guide

• [X] - Please check this box once you've submitted the PR if you've read through the Contribution Guide and best practices checklist.

Changelog

• Converted the main deployment to Bicep
• Converted the prereq deployment to Bicep
• Attached an NSG to the prereq subnets