Bazel Basic Tests for Python (Local) failure //src/python/grpcio_tests/tests/qps:basic_benchmark_test

Seen on #17806.. The result store shows that it has been failing since #17644 got introduced.

Log https://source.cloud.google.com/results/invocations/1d758624-905d-41ed-bb09-8b2a6df16938/targets
