In bbr2sender::adjustnetworkparameters, 1) do not inject a bandwidth sample to max bandwidth filter, and 2) update pacing rate after cwnd is updated. protected by --gfe2_reloadable_flag_quic_bbr2_improve_adjust_network_parameters. PiperOrigin-RevId: 321198508 Change-Id: I4366a2b159c48302eaf935784dfb7d093d322257