gfe-relnote: In QUIC bandwidth sampler, only remove packets when RemoveObsoletePackets is called. Protected by --gfe2_reloadable_flag_quic_bw_sampler_remove_packets_once_per_congestion_event.

PiperOrigin-RevId: 285110271
Change-Id: I27567839a190136c03fef54a66261ab34d8c1f82
diff --git a/quic/core/congestion_control/bbr_sender.cc b/quic/core/congestion_control/bbr_sender.cc
index 8441455..4973744 100644
--- a/quic/core/congestion_control/bbr_sender.cc
+++ b/quic/core/congestion_control/bbr_sender.cc
@@ -495,7 +495,7 @@
 
 void BbrSender::DiscardLostPackets(const LostPacketVector& lost_packets) {
   for (const LostPacket& packet : lost_packets) {
-    sampler_.OnPacketLost(packet.packet_number);
+    sampler_.OnPacketLost(packet.packet_number, packet.bytes_lost);
     if (mode_ == STARTUP) {
       if (stats_) {
         ++stats_->slowstart_packets_lost;