fix: test_blob_acl_w_metageneration_match due to Public access prevention

tests/system/test_blob.py

@@ -425,26 +425,23 @@ def test_blob_acl_w_metageneration_match(
 
     # Exercise blob ACL with metageneration/generation match
     acl = blob.acl
-    blob.reload()
+    acl.domain("google.com").grant_read()
 
     with pytest.raises(exceptions.PreconditionFailed):
-        acl.save_predefined(
-            "publicRead", if_metageneration_match=wrong_metageneration_number
-        )
-        assert "READER" not in acl.all().get_roles()
+        acl.save(if_metageneration_match=wrong_metageneration_number)
+        assert "READER" not in acl.domain("google.com").get_roles()
 
-    acl.save_predefined("publicRead", if_metageneration_match=blob.metageneration)
-    assert "READER" in acl.all().get_roles()
+    acl.save(if_metageneration_match=blob.metageneration)
 
-    blob.reload()
-    del acl.entities["allUsers"]
+    assert "READER" in acl.domain("google.com").get_roles()
+    acl.domain("google.com").revoke_read()
 
     with pytest.raises(exceptions.PreconditionFailed):
         acl.save(if_generation_match=wrong_generation_number)
-        assert acl.has_entity("allUsers")
+        assert "READER" in acl.domain("google.com").get_roles()
 
     acl.save(if_generation_match=blob.generation)
-    assert not acl.has_entity("allUsers")
+    assert "READER" not in acl.domain("google.com").get_roles()
 
 
 def test_blob_acl_upload_predefined(
@@ -453,31 +450,32 @@ def test_blob_acl_upload_predefined(
     file_data,
     service_account,
 ):
-    control = shared_bucket.blob(f"logo{uuid.uuid4().hex}")
-    control_info = file_data["logo"]
+    control_blob = shared_bucket.blob(f"logo{uuid.uuid4().hex}")
+    control_blob_info = file_data["logo"]
 
     blob = shared_bucket.blob(f"SmallFile{uuid.uuid4().hex}")
     info = file_data["simple"]
 
     try:
-        control.upload_from_filename(control_info["path"])
+        control_blob.upload_from_filename(control_blob_info["path"])
     finally:
-        blobs_to_delete.append(control)
-
+        blobs_to_delete.append(control_blob)
     try:
-        blob.upload_from_filename(info["path"], predefined_acl="publicRead")
+        blob.upload_from_filename(info["path"], predefined_acl="private")
     finally:
         blobs_to_delete.append(blob)
 
-    control_acl = control.acl
-    assert "READER" not in control_acl.all().get_roles()
+    control_blob_acl = control_blob.acl
 
     acl = blob.acl
-    assert "READER" in acl.all().get_roles()
-
-    acl.all().revoke_read()
-    assert acl.all().get_roles() == set()
-    assert control_acl.all().get_roles() == acl.all().get_roles()
+    count = 0
+    for entry in acl:
+        count += 1
+        entity = entry["entity"]
+    assert count == 1
+    assert entity.lstrip("user-") == service_account.service_account_email
+
+    assert sum(1 for _ in control_blob_acl) > 1
 
 
 def test_blob_patch_metadata(