When packet arrives with large gap majority of the time could be spend in finding next received packet. Embedding such search into PacketArrivalMap makes it faster Bug: chromium:1373414 Change-Id: I2e0be0f2fc4ea96af081531d575a17c70b72b25b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/279881 Reviewed-by: Emil Lundmark <lndmrk@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#38459}