fix starlette default span details

Author: macieyng

instrumentation/opentelemetry-instrumentation-starlette/src/opentelemetry/instrumentation/starlette/__init__.py

@@ -278,7 +278,7 @@ def __init__(self, *args, **kwargs):
         self.add_middleware(
             OpenTelemetryMiddleware,
             excluded_urls=_excluded_urls,
-            default_span_details=_get_route_details,
+            default_span_details=_get_default_span_details,
             server_request_hook=_InstrumentedStarlette._server_request_hook,
             client_request_hook=_InstrumentedStarlette._client_request_hook,
             client_response_hook=_InstrumentedStarlette._client_response_hook,