PR Summary

1. Add the pipeline YAML file for publishing .msixbundle package as a VPack.
2. Update AppxManifest.xml to include the PhoneIdentity tag, which is required to be the same between a pre-installed app and its store version. See https://www.osgwiki.com/wiki/Adding_a_Preinstalled_App#PhoneProductID_in_the_manifest_needs_to_match_values_from_the_Store for more information.
3. Update the packaging.psm1 file to include the PhoneProductId for Microsoft.PowerShell and Microsoft.PowerShellPreview respectively.
4. Minor updates to SetVersionVariables.yml to fix typos and make the display of environment variables readable.
5. Minor updates to the release pipeline to include the new msixbundle-vpack pipeline.

• msixbundle-vpack pipeline test run: https://dev.azure.com/mscodehub/PowerShellCore/_build/results?buildId=597669&view=results
• PowerShell build pipeline test run: https://dev.azure.com/mscodehub/PowerShellCore/_build/results?buildId=597785&view=results
• PowerShell package pipeline test run: https://dev.azure.com/mscodehub/PowerShellCore/_build/results?buildId=598140&view=results -- the windows_package stage was successful and .msix packages were produced with the expected PhoneProductID.