Increase the margin on bandwidth over-estimation when the B204 connection option is present to avoid flakes.

PiperOrigin-RevId: 401096992
diff --git a/quic/core/congestion_control/bbr2_simulator_test.cc b/quic/core/congestion_control/bbr2_simulator_test.cc
index fc43997..490996b 100644
--- a/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -978,7 +978,7 @@
   // This is much farther off when aggregation is present,
   // Ideally BSAO or another option would fix this.
   EXPECT_APPROX_EQ(params.test_link.bandwidth,
-                   sender_->ExportDebugState().bandwidth_est, 0.50f);
+                   sender_->ExportDebugState().bandwidth_est, 0.55f);
   EXPECT_LE(sender_loss_rate_in_packets(), 0.35);
   EXPECT_LE(sender_->ExportDebugState().max_ack_height, 10000u);