Reland "media/gpu/v4l2: increase allocated video buffers on stateful backends"

This reverts commit 33dd60a2353c398dac3e9685379a865e1adee349.

Reason for revert: CTS failures (b:257880924) on VAAPI boards shows VAAPI is effected by this buffer allocation, but not V4L2.  This CL setup for the follow on.  Since that one has been reverted, revert this one as well to get back to the improved V4L2 state, but not VAAPI impacted state.

Original change's description:
> Revert "media/gpu/v4l2: increase allocated video buffers on stateful backends"
>
> This reverts commit b81d1376b2a09109d361dd56986e62eccd8cd7af.
>
> This is to allow the next CL in the series, where the amount
> of video buffers is calculated in VideoDecoderPipeline.
>
>
> Bug: b:250187354
> Bug: b:254657177
>
> Change-Id: If28ba47e13977324dc42d3bd6f22a33a3f7ad469
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3980635
> Reviewed-by: Fritz Koenig <frkoenig@chromium.org>
> Commit-Queue: Miguel Casas-Sanchez <mcasas@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1066564}

Bug: b:250187354
Bug: b:254657177
Change-Id: I640e2a81c8a76ccc1aa50ca31c19732c80ebfafe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4018212
Commit-Queue: Fritz Koenig <frkoenig@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1069362}