Fix VP9_Simulcast_SwitchToLegacySvc flakiness.

https://luci-analysis.appspot.com/p/webrtc/clusters/testname-v4/5f33a918de6eb10b2b14ec5f2bd22d3a?tab=recent-failures

Change-Id: I7c8e3b81c25a97e13b328065567712c85942e32d
Bug: None
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/356320
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42584}
diff --git a/pc/peer_connection_encodings_integrationtest.cc b/pc/peer_connection_encodings_integrationtest.cc
index 7b805bb..a497acb 100644
--- a/pc/peer_connection_encodings_integrationtest.cc
+++ b/pc/peer_connection_encodings_integrationtest.cc
@@ -945,7 +945,7 @@
   // and two are active.
   ASSERT_TRUE_WAIT(HasOutboundRtpBytesSent(local_pc_wrapper, /*num_layers=*/3u,
                                            /*num_active_layers=*/2u),
-                   kDefaultTimeout.ms());
+                   kLongTimeoutForRampingUp.ms());
   // Wait until scalability mode is reported and expected resolution reached.
   // Ramp up time may be significant.
   ASSERT_TRUE_WAIT(HasOutboundRtpWithRidAndScalabilityMode(