libgav1: update snapshot to cl/263885228

+cl/264669395
significantly improves performance, this version now outperforms the
libaom based decoder.

Bug: 130249450
Test: aosp_arm-eng aosp_arm64-eng aosp_x86-eng aosp_x86_64-eng build
Test: cts-tradefed run commandAndExit cts-dev --include-filter CtsMediaTestCases --module-arg "CtsMediaTestCases:include-filter:android.media.cts.DecoderTest#testAV1*" --module-arg "CtsMediaTestCases:include-filter:android.media.cts.AdaptivePlaybackTest#testAV1*" (bonito-userdebug)
Test: (externally) libaom/Argon/Allegro test vectors, cpu/memory performance, fuzzing

Change-Id: Ie23ebe0d761bf1896a7acab112b7f2574d7b1065
(cherry picked from commit 3ef2dfa5357309adbaa94c82511a3e9003926da2)
147 files changed