设置est->cur_bitrate，是否需要同时将bwe和delay码率也重置呢？

[adcen0107]

void sender_estimation_set_send_bitrate(sender_estimation_t* est, uint32_t send_bitrate)
{
razor_debug("sender_estimation_set_send_bitrate, bitrate = %u\n", send_bitrate);
est->bwe_incoming = est->delay_base_bitrate = 0; //是否需要添加这个，否则est->cur_bitrate仍旧受旧bwe,delay速率影响
cap_bitrate_to_threshold(est, GET_SYS_MS(), send_bitrate);

/*清空历史最小记录*/
est->end_index = est->begin_index = 0;

}