If all packets are dropped for a period of time, an observation window will have the same length as the period when packets are dropped.
If later, no packets are lost, there is no point in loss based bwe backing down.
Therefore, ignore the observation with most loss and least loss when calculating an instant upper bound.
Bug: webrtc:42222865
Change-Id: I1d0125d6c76e68018b2aec1ecaa9b65729963136
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/356380
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Diep Bui <diepbp@google.com>
Cr-Commit-Position: refs/heads/main@{#42772}