Fix service version

Author: gvdongen

google-adk/tour-of-agents/app/sub_workflow_agent.py

@@ -57,7 +57,7 @@ async def human_approval(claim: InsuranceClaim) -> str:
 app = App(name=APP_NAME, root_agent=agent, plugins=[RestatePlugin()])
 session_service = InMemorySessionService()
 
-agent_service = restate.VirtualObject("SubWorkflowClaimApprovalAgent")
+agent_service = restate.Service("SubWorkflowClaimApprovalAgent")
 
 
 # HANDLER