gfe-relnote: For server side QUIC connection, mark version_negotiated_ earlier. Protected by --gfe2_reloadable_flag_quic_version_negotiated_by_default_at_server.

PiperOrigin-RevId: 282365816
Change-Id: I9083e05d758f564befaab126e427f7ab434d2f6f
diff --git a/quic/core/quic_session.cc b/quic/core/quic_session.cc
index cba27f0..2870b37 100644
--- a/quic/core/quic_session.cc
+++ b/quic/core/quic_session.cc
@@ -114,6 +114,13 @@
   connection_->SetDataProducer(this);
   connection_->SetFromConfig(config_);
 
+  // On the server side, version negotiation has been done by the dispatcher,
+  // and the server session is created with the right version.
+  if (connection_->quic_version_negotiated_by_default_at_server() &&
+      perspective() == Perspective::IS_SERVER) {
+    connection_->OnSuccessfulVersionNegotiation();
+  }
+
   if (QuicVersionUsesCryptoFrames(transport_version())) {
     return;
   }