update validation app endpoint to test

Author: yiyuan-he

sample-applications/integ-test-app/udp_exporter_validation_app.py

@@ -22,7 +22,7 @@
 # Get tracer
 tracer = trace.get_tracer(__name__)
 
-@app.route('/trace', methods=['GET'])
+@app.route('/test', methods=['GET'])
 def create_trace():
     # Create a span for testing with various attributes
     tracer = trace.get_tracer(__name__)