Rationalize EXPOSE instructions

[richlander]

EXPOSE instructions should have the following characteristics:

• Match ASP.NET Core defaults.
• No TLS/HTTPS since that's a deployment concern

Ideally, we wouldn't need to use EXPOSE at all, but I'm guessing that VS Code relies on it.

https://github.com/search?q=repo%3Adotnet%2FAspNetCore.Docs.Samples%20EXPOSE&type=code

FYI for .NET 8: dotnet/core#8133 (comment)