Do not export gfe2_reloadable_flag_quic_max_age_send_goaway to QUICHE.

This flag is only used in internal code.

PiperOrigin-RevId: 343155211
Change-Id: I1b8c399f7113f04c59290a7d25efef2c553b7c3f

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index c246877..6ccb354 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -61,7 +61,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_granular_qpack_error_codes, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_key_update_supported, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_let_connection_handle_pings, true)
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_max_age_send_goaway, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_new_priority_update_frame, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_process_undecryptable_packets_after_async_decrypt_callback, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_record_received_min_ack_delay, true)