fix agentframework trace init

Author: lusu-msft

sdk/agentserver/azure-ai-agentserver-agentframework/azure/ai/agentserver/agentframework/agent_framework.py

@@ -80,19 +80,18 @@ def init_tracing(self):
         app_insights_conn_str = os.environ.get(APPINSIGHT_CONNSTR_ENV_NAME)
         project_endpoint = os.environ.get(AdapterConstants.AZURE_AI_PROJECT_ENDPOINT)
 
-        if project_endpoint:
-            project_client = AIProjectClient(endpoint=project_endpoint, credential=DefaultAzureCredential())
-            agent_client = AzureAIAgentClient(project_client=project_client)
-            agent_client.setup_azure_ai_observability()
-        elif exporter or app_insights_conn_str:
-            os.environ["WORKFLOW_ENABLE_OTEL"] = "true"
+        if exporter or app_insights_conn_str:
             from agent_framework.observability import setup_observability
 
             setup_observability(
                 enable_sensitive_data=True,
                 otlp_endpoint=exporter,
                 applicationinsights_connection_string=app_insights_conn_str,
             )
+        elif project_endpoint:
+            project_client = AIProjectClient(endpoint=project_endpoint, credential=DefaultAzureCredential())
+            agent_client = AzureAIAgentClient(project_client=project_client)
+            agent_client.setup_azure_ai_observability()
         self.tracer = trace.get_tracer(__name__)
 
     async def agent_run(