In IETF QUIC, stop packet processing if PATH_RESPONSE frame triggers connection close.

Protected by quic_reloadable_flag_quic_pass_path_response_to_validator.

PiperOrigin-RevId: 346422741
Change-Id: Ie91739253cf68f1dd0be5f535853f76a98b40553

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index c3c3fb2..3926404 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -1610,7 +1610,7 @@
     // Have received the matching PATH RESPONSE, saved payload no longer valid.
     transmitted_connectivity_probe_payload_ = nullptr;
   }
-  return true;
+  return connected_;
 }
 
 bool QuicConnection::OnConnectionCloseFrame(