Update the visual studio version checking logic
Update the visual studio version checking logic

This PR updates the `_is_vs_2017_or_2019` function to specify the visual studio version based on the contents of the VC folder instead of depending on the parent directories of VC.

This is helpful in cases where `BAZEL_VC` points to a custom location of VC.

Fixes: #11259

Closes #12586.

PiperOrigin-RevId: 344817390

cushon/bazel,perezd/bazel,katre/bazel,cushon/bazel,perezd/bazel,ButterflyNetwork/bazel,perezd/bazel,safarmer/bazel,twitter-forks/bazel,twitter-forks/bazel,bazelbuild/bazel,katre/bazel,katre/bazel,perezd/bazel,cushon/bazel,katre/bazel,safarmer/bazel,safarmer/bazel,twitter-forks/bazel,meteorcloudy/bazel,bazelbuild/bazel,ButterflyNetwork/bazel,perezd/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,safarmer/bazel,meteorcloudy/bazel,katre/bazel,twitter-forks/bazel,perezd/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,twitter-forks/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,perezd/bazel,safarmer/bazel,meteorcloudy/bazel,cushon/bazel,bazelbuild/bazel,meteorcloudy/bazel,twitter-forks/bazel,bazelbuild/bazel,cushon/bazel,meteorcloudy/bazel,katre/bazel,safarmer/bazel,meteorcloudy/bazel,cushon/bazel,meteorcloudy/bazel