Enable tests on container-based Linux legs and determine what tests should run there

[MiYanni]

Summary

As part of the migration for dotnet/installer into dotnet/sdk, we've added many Linux legs that utilize containers. I've set up the pipeline to allow these to run tests appropriately.

However, there are issues:

• There are MANY tests and we may not want to run ALL tests on every container job.
• Some tests won't work on certain containers. We work around this within the method below, but the logic needs to be expanded for the other Linux flavors (such as debian).
  • https://github.com/dotnet/sdk/blob/main/test/Microsoft.NET.TestFramework/EnvironmentInfo.cs#L63
• When I ran these jobs, there are some test failures that either may be legitimate or the tests need to be adjusted.
• The tests from the dotnet/installer repo are currently not being ran as they aren't converted to Helix tests yet. We may want to run these tests on these container jobs.

For the time being, we've disabled running tests on these jobs.