verify gfe2_reloadable_flag_quic_unify_stop_sending.

The flag protected change is dealing with a corner case which didn't occur in Canary.
Since the change is technically a refactor with no behavior impact, maybe we can flip it on without flag count.

PiperOrigin-RevId: 362088532
Change-Id: Ic6398b00a8e2a059e677e698be7935329beef929

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index 8652332..3e49d0e 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -65,7 +65,7 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_tls_use_normalized_sni_for_cert_selectioon, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_tls_use_per_handshaker_proof_source, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_unified_iw_options, false)
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_unify_stop_sending, false)
+QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_unify_stop_sending, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_update_packet_content_returns_connected, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_use_encryption_level_context, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_use_write_or_buffer_data_at_level, false)