Disable gfe2_restart_flag_quic_default_on_ietf_loss_detection in QuicEndpointTest.Competition while investigating the issue.

gfe-relnote: n/a(test only change)
PiperOrigin-RevId: 290807785
Change-Id: Ia97e44050f936d3d7dd9fe173a9b747f170f561b

quic/test_tools/simulator/quic_endpoint_test.cc

diff --git a/quic/test_tools/simulator/quic_endpoint_test.cc b/quic/test_tools/simulator/quic_endpoint_test.cc
index 0989a3b..ae53aee 100644
--- a/quic/test_tools/simulator/quic_endpoint_test.cc
+++ b/quic/test_tools/simulator/quic_endpoint_test.cc
@@ -157,6 +157,8 @@
 TEST_F(QuicEndpointTest, Competition) {
   // TODO(63765788): Turn back on this flag when the issue if fixed.
   SetQuicReloadableFlag(quic_bbr_one_mss_conservation, false);
+  // TODO(b/147922970): Turn back on this flag when the issue is fixed.
+  SetQuicRestartFlag(quic_default_on_ietf_loss_detection, false);
   auto endpoint_a = std::make_unique<QuicEndpoint>(
       &simulator_, "Endpoint A", "Endpoint D (A)", Perspective::IS_CLIENT,
       test::TestConnectionId(42));