Tests passing locally... try sleep before server stop

Author: chusitoo

exporters/otlp/test/otlp_http_exporter_test.cc

@@ -775,6 +775,8 @@ TEST_P(OtlpHttpExporterRetryIntegrationTests, StatusCodes)
   auto provider  = trace_sdk::TracerProviderFactory::Create(std::move(processor));
   provider->GetTracer("Test tracer")->StartSpan("Test span")->End();
   provider->ForceFlush();
+
+  std::this_thread::sleep_for(std::chrono::milliseconds{500});
   server.stop();
 
   ASSERT_EQ(expected_attempts, request_count);