gfe-relnote: In QUIC, when doing cwnd bootstrap, slow pacing rate if it is likely causing overshoot. Protected by gfe2_reloadable_flag_quic_bbr_mitigate_overly_large_bandwidth_sample. PiperOrigin-RevId: 288958446 Change-Id: Ia076b0f27d7d9302aa567a8577b25b0ad10da7cc