gfe-relnote: In QUIC, do not inject bandwidth in BbrSender::AdjustNetworkParameters. Also use min rtt instead of srtt when calculating new cwnd. Protected by gfe2_reloadable_flag_quic_bbr_donot_inject_bandwidth. PiperOrigin-RevId: 279119475 Change-Id: I6bca045fd27926321e1984b41849dd406f6fe6ab