test(gemini realtime): wrap test_gemini_tool_call_resets_ids fixture in setup envelope

The cached session_configuration_request the proxy stores is always
serialized as {"setup": ...}; this test passed a bare config dict, so
transform_session_created_event's .get('setup', {}) returned an empty
dict and the responseModalities lookup ran against the default rather
than the fixture. Wrap the fixture in the same shape the production
cache uses.

tests/test_litellm/llms/gemini/realtime/test_gemini_realtime_transformation.py

@@ -772,8 +772,10 @@ def test_gemini_tool_call_resets_ids_for_post_tool_model_turn():
 
     session_configuration_request = json.dumps(
         {
-            "model": "gemini-1.5-flash",
-            "generationConfig": {"responseModalities": ["TEXT"]},
+            "setup": {
+                "model": "gemini-1.5-flash",
+                "generationConfig": {"responseModalities": ["TEXT"]},
+            }
         }
     )