[media] Convert unique_ptr<T[]> to HeapArray<T>

See
https://docs.google.com/document/d/1YsPR8GoN8VTP1ABKCISaQkuBif1Cn80cTxTjsM8QT4s
for an explanation on why this is favorable.

Bug: b/326458792, b/326459116, b/326459256
Change-Id: I592552958fdd3a002f99814a89b3df89c866ead9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5467185
Reviewed-by: John Rummell <jrummell@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Feras Aldahlawi <feras@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1290155}
NOKEYCHECK=True
GitOrigin-RevId: c863b37bdafa5f6ec12d0b9ad8dc79e69384551e
1 file changed