refactor: rename agent_dir to agents_dir and rename app_id to app_name in fast_api.py to make it consistent among every endpoints

PiperOrigin-RevId: 763483339

tests/unittests/fast_api/test_fast_api.py

@@ -308,7 +308,7 @@ def test_app(mock_session_service, mock_artifact_service, mock_memory_service):
   ):
     # Get the FastAPI app, but don't actually run it
     app = get_fast_api_app(
-        agent_dir=".", web=True, session_db_url="", allow_origins=["*"]
+        agents_dir=".", web=True, session_db_url="", allow_origins=["*"]
     )
 
     # Create a TestClient that doesn't start a real server

tests/unittests/testing_utils.py

@@ -202,7 +202,7 @@ class InMemoryRunner:
         session_id=self.session.id,
         new_message=get_user_content(new_message),
     ):
-        events.append(event)
+      events.append(event)
     return events
 
   def run_live(self, live_request_queue: LiveRequestQueue) -> list[Event]: