gfe-relnote: QUIC_BUG instead of LOG(ERROR) in CreateQuicVersionLabel if the HandshakeProtocol is unknown

QuicFramer::ProcessVersionNegotiationPacket also filters out unknown versions before
saving them to the QuicVersionNegotiationPacket struct.
PiperOrigin-RevId: 251515152
Change-Id: I8b4ed34ff59e1760051e42b5659e5acc987d7ee3
diff --git a/quic/core/quic_framer.cc b/quic/core/quic_framer.cc
index df019cf..27237d7 100644
--- a/quic/core/quic_framer.cc
+++ b/quic/core/quic_framer.cc
@@ -1572,7 +1572,10 @@
           DroppedPacketReason::INVALID_VERSION_NEGOTIATION_PACKET);
       return RaiseError(QUIC_INVALID_VERSION_NEGOTIATION_PACKET);
     }
-    packet.versions.push_back(ParseQuicVersionLabel(version_label));
+    ParsedQuicVersion parsed_version = ParseQuicVersionLabel(version_label);
+    if (parsed_version != UnsupportedQuicVersion()) {
+      packet.versions.push_back(parsed_version);
+    }
   } while (!reader->IsDoneReading());
 
   QUIC_DLOG(INFO) << ENDPOINT << "parsed version negotiation: "