test: Add test to ensure RunConfig instances do not share audio transcription configs

The new test verifies that `output_audio_transcription` and `input_audio_transcription` attributes are unique to each `RunConfig` instance, preventing unintended side effects from modifying one instance.

PiperOrigin-RevId: 806405671

Author: hangfei

tests/unittests/agents/test_run_config.py

@@ -1,4 +1,17 @@
-import logging
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import sys
 from unittest.mock import ANY
 from unittest.mock import patch
@@ -31,3 +44,23 @@ def test_validate_max_llm_calls_too_large():
       ValueError, match=f"max_llm_calls should be less than {sys.maxsize}."
   ):
     RunConfig.validate_max_llm_calls(sys.maxsize)
+
+
+def test_audio_transcription_configs_are_not_shared_between_instances():
+  config1 = RunConfig()
+  config2 = RunConfig()
+
+  # Validate output_audio_transcription
+  assert config1.output_audio_transcription is not None
+  assert config2.output_audio_transcription is not None
+  assert (
+      config1.output_audio_transcription
+      is not config2.output_audio_transcription
+  )
+
+  # Validate input_audio_transcription
+  assert config1.input_audio_transcription is not None
+  assert config2.input_audio_transcription is not None
+  assert (
+      config1.input_audio_transcription is not config2.input_audio_transcription
+  )