Replace ArrayView::subview with subspan in logging/

Fix ExtendLoggedBatch function to produce expected resolut when
`!output.empty()`. In particular avoid calling subspan function and
discard result as that would be a compilation error with std::span.

Bug: webrtc:439801349
Change-Id: I4a8e372417c974c796ec4eb5e1d406b13b59fa4b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/447061
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#46857}