During a seek, or when playing a media with clipped start,
MCVR encounters preroll decode-only buffers that are not rendered.
Use C.BUFFER_FLAG_NO_OTHER_SAMPLE_DEPENDS_ON_THIS to determine
whether a decode-only buffer is unused as reference.
These buffers can be dropped before the decoder.
When this optimization is triggered, increment
decoderCounters.skippedInputBufferCount.
Tested in ExoPlayer demo app on "One hour frame counter (MP4)"
after enabling extractorsFactory.setMp4ExtractorFlags(
FLAG_READ_WITHIN_GOP_SAMPLE_DEPENDENCIES);
Observe: "sib" increases on each seek.
PiperOrigin-RevId: 650566216
6650270a4e