Added checks to the packaging script to detect running on Ubuntu 20.04 distribution, so that if Powershell is packaged and/or run in a sandbox it can perform accordingly for the Ubuntu 20.04 distribution/package, by getting its package dependencies (which matches that of its preview Dockerfile) and validating the platform to differentiate it from other valid platforms.

Helps to provide validation for the Ubuntu20.04 distribution and get the appropriate package dependencies and validation when its packaged up.

Related to #12626

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