cumulative lost is always signed now. Bug: webrtc:9598 Change-Id: I7cf9f87c01a60fafc3fa6a9bdb84950343697193 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/301940 Auto-Submit: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Björn Terelius <terelius@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#39905}