…ter (#1757)

Co-authored-by: Kira <kirnendra@google.com>

feat: Triger bidi conformance tests

Changes / fixes

- When (read/write) stream breaks, don't do `.close` on it. (this leads
to reading the same error message again and again until retry loop times
out)
- Bidi Conf test were ran directly as a module , change that so that
they get triggered in Kokoro (done that by adding `test_` so that pytest
pickup the tests)
- Provide a way to create anonymous connection in grpc client. 
- Unit tests and other minor changes.



~blocked because of b/489420625~

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

…ironments (#1757)

This prevents extra authentication and default location queries in
multithreaded environments.