Python SDK tests are failing if no GOOGLE_APPLICATION_CREDENTIALS was set

Running locally mvn clean install fails on following Apache Beam :: SDKs :: Python tests:

ERROR: test_message_matcher_mismatch (apache_beam.io.gcp.tests.pubsub_matcher_test.PubSubMatcherTest)
ERROR: test_message_matcher_success (apache_beam.io.gcp.tests.pubsub_matcher_test.PubSubMatcherTest)
ERROR: test_message_metcher_timeout (apache_beam.io.gcp.tests.pubsub_matcher_test.PubSubMatcherTest)

with an error:

DefaultCredentialsError: Could not automatically determine credentials. Please set GOOGLE_APPLICATION_CREDENTIALS or
explicitly create credential and re-run the application. For more
information, please see
https://developers.google.com/accounts/docs/application-default-credentials.
-------------------- >> begin captured logging << --------------------
google.auth.transport._http_client: DEBUG: Making request: GET http://169.254.169.254
google.auth.compute_engine._metadata: INFO: Compute Engine Metadata server unavailable.
--------------------- >> end captured logging << ---------------------

It looks like it's a regression and it was caused by this commit: 301853647f2c726c04c5bdb02cab6ff6b39f09d0