Fix quic::GetPacketHeaderSize when QuicVersionHasLongHeaderLengths is false

gfe-relnote: Bugfix in quic::GetPacketHeaderSize protected by gfe2_reloadable_flag_quic_fix_get_packet_header_size
PiperOrigin-RevId: 256043642
Change-Id: I1f943400e15a684b5cb84f2a11cbb294859f669e
diff --git a/quic/test_tools/quic_packet_creator_peer.h b/quic/test_tools/quic_packet_creator_peer.h
index e040090..f8f3d59 100644
--- a/quic/test_tools/quic_packet_creator_peer.h
+++ b/quic/test_tools/quic_packet_creator_peer.h
@@ -57,6 +57,7 @@
 
   static EncryptionLevel GetEncryptionLevel(QuicPacketCreator* creator);
   static QuicFramer* framer(QuicPacketCreator* creator);
+  static void EnableGetPacketHeaderSizeBugFix(QuicPacketCreator* creator);
 };
 
 }  // namespace test