Fix _define_auto_test for different ways of invoking the test.
Fix _define_auto_test for different ways of invoking the test.

The test in the previous commit would work when being run directly, but fail when invoked by pytest.

PiperOrigin-RevId: 364822266
Change-Id: I808002529f856d33e4150296914f0868e7136961

deepmind/fancyflags