QUIC+TLS server should temporarily retain 0-RTT keys so that re-ordered packets can be decoded.

Protected by FLAGS_quic_restart_flag_quic_server_temporarily_retain_tls_zero_rtt_keys.

PiperOrigin-RevId: 345557425
Change-Id: I27f0a13c98d7362ed702de26c33215252e686d2b
diff --git a/quic/core/quic_connection_stats.cc b/quic/core/quic_connection_stats.cc
index d7440b4..a693677 100644
--- a/quic/core/quic_connection_stats.cc
+++ b/quic/core/quic_connection_stats.cc
@@ -58,6 +58,8 @@
   os << " key_update_count: " << s.key_update_count;
   os << " num_failed_authentication_packets_received: "
      << s.num_failed_authentication_packets_received;
+  os << " num_tls_server_zero_rtt_packets_received_after_discarding_decrypter: "
+     << s.num_tls_server_zero_rtt_packets_received_after_discarding_decrypter;
   os << " }";
 
   return os;