Mvc.Analyzer test code exceeds MAX_PATH

[HaoK]

Similar to #7882

https://github.com/aspnet/AspNetCore/tree/master/src/Mvc/Mvc.Api.Analyzers/test/TestFiles and https://github.com/aspnet/AspNetCore/tree/master/src/Mvc/Mvc.Analyzers/test/TestFiles which causes helix to reject these work items since the combined path is too long

cc @dougbu

[dougbu]

@HaoK how urgent is this issue? I'm hoping I can do this next week, not this one.

[HaoK]

Not urgent at this point, whenever you can get to it is fine

[mkArtakMSFT]

@pranavkm reassigning this to you to handle in a future milestone.

[dougbu]

@mkArtakMSFT this is an area-infrastructure issue I was planning to handle next week.

@pranavkm let me know if you would like me to take it back.

/fyi @natemcmaster