fix: Update tests for coverage of all branches

Signed-off-by: Radhika Agrawal <agrawalradhika@google.com>

Author: agrawalradhika-cell

tests/unit/operations_v1/test_operations_rest_client.py

@@ -351,11 +351,16 @@ def test_operations_client_client_options(
     with mock.patch.dict(
         os.environ, {"GOOGLE_API_USE_CLIENT_CERTIFICATE": "Unsupported"}
     ):
-        if hasattr(google.auth.transport.mtls, "should_use_client_cert"):
-            pytest.skip(
-                "The should_use_client_cert function is available in this "
-                "version of google-auth. Skipping this test."
-            )
+        if not hasattr(google.auth.transport.mtls, "should_use_client_cert"):
+            with pytest.raises(ValueError):
+                client = client_class()
+        else:
+             with mock.patch.object(transport_class, "__init__") as patched:
+                patched.return_value = None
+                client = client_class(
+                    credentials=ga_credentials.AnonymousCredentials(),
+                    transport=transport_name
+                )
 
     # Check the case quota_project_id is provided
     options = client_options.ClientOptions(quota_project_id="octopus")