fix(tests): use mock GCS client in artifact service tests to avoid real credentials

Copybara import of the project:

--
ade1d98e030a966183f56cb5c9c1b04cf51f5337 by Thiago Neves <thiagohneves@gmail.com>:

fix(tests): use mock GCS client in artifact service tests to avoid real credentials

--
becd2925feebf60196129b029a0ab8d490f7b19e by Thiago Neves <thiagohneves@gmail.com>:

test(agents): add unit tests for live_request_queue, readonly_context, and run_config

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/641 from thiagoneves:feature/increase-test-coverage 0f7a9fc55d97902e190a394f099324fbeb1541af
PiperOrigin-RevId: 756798390

tests/unittests/agents/test_run_config.py

@@ -0,0 +1,31 @@
+import pytest
+import sys
+import logging
+from unittest.mock import patch, ANY
+from google.adk.agents.run_config import RunConfig
+
+
+def test_validate_max_llm_calls_valid():
+  value = RunConfig.validate_max_llm_calls(100)
+  assert value == 100
+
+
+def test_validate_max_llm_calls_negative():
+  with patch("google.adk.agents.run_config.logger.warning") as mock_warning:
+    value = RunConfig.validate_max_llm_calls(-1)
+    mock_warning.assert_called_once_with(ANY)
+    assert value == -1
+
+
+def test_validate_max_llm_calls_warns_on_zero():
+  with patch("google.adk.agents.run_config.logger.warning") as mock_warning:
+    value = RunConfig.validate_max_llm_calls(0)
+    mock_warning.assert_called_once_with(ANY)
+    assert value == 0
+
+
+def test_validate_max_llm_calls_too_large():
+  with pytest.raises(
+      ValueError, match=f"max_llm_calls should be less than {sys.maxsize}."
+  ):
+    RunConfig.validate_max_llm_calls(sys.maxsize)