chore: fixes flaky test (GoogleCloudPlatform#4815)

* chore: fixes flaky test
fixes GoogleCloudPlatform#4794

* chore: fixes flaky test
Fixes GoogleCloudPlatform#4793
Removes assertion which the backend inconsistently satifies.

Author: danoscarmike

video/cloud-client/analyze/video_detect_faces_beta_test.py

@@ -30,4 +30,3 @@ def test_detect_faces(capsys):
     out, _ = capsys.readouterr()
 
     assert "Face detected:" in out
-    assert "Attributes:" in out

video/cloud-client/analyze/video_detect_faces_gcs_beta_test.py

@@ -30,4 +30,3 @@ def test_detect_faces(capsys):
     out, _ = capsys.readouterr()
 
     assert "Face detected:" in out
-    assert "Attributes:" in out