"Interoperability" is a more appropriate name for the tests, since they
are used for testing across different implementations. They will do a
bit of integration testing, like for auth, but this is a smaller scale.
It seems the other languages (Go, C++, Node, PHP, Python, Ruby) are
using "interop" to describe the tests, and the test case specifications
document is named with "interop". After this change, C# will be the only
language calling them "integration" tests.
This change just renames the folder and artifact. We can change the
internal package names later. However, once we do a release, old
artifact names will live forever in Maven Central.