[NvidiaLinux] Use BufferUsage::SCANOUT for GMB video frames to support NVIDIA drivers

On Linux, GpuMemoryBuffer video frames created with
BufferUsage::SCANOUT_CPU_READ_WRITE implicitly request
GBM_BO_USE_LINEAR, which is incompatible with rendering on certain
NVIDIA drivers.

This incompatibility prevents rendering in CEF shared texture and video
capture pipelines.

Switching to BufferUsage::SCANOUT avoids GBM_BO_USE_LINEAR while
retaining GBM_BO_USE_RENDERING, GBM_BO_USE_SCANOUT, and
GBM_BO_USE_TEXTURING, enabling Skia-based rendering and texture interop
to work correctly with NVIDIA drivers.

To support this a new value kPreferSharedImageWithNativeHandle, was
added to the BufferFormatPreference enum, which indicates that the
consumer prefers buffers with exportable GPU native handles (e.g.,
DMABUF FDs on Linux). These buffers may not be CPU mappable, but are
better suited for GPU interop scenarios such as Vulkan, Skia, or
offscreen rendering with shared textures.

The preference is propagated through the capture pipeline:

Start() receives the BufferFormatPreference from the client.

This preference is passed to VideoFramePool, then to
RenderableGpuMemoryBufferVideoFramePool.

FrameResources::Initialize() uses this to choose between
SCANOUT_CPU_READ_WRITE (default) and SCANOUT, depending on whether CPU
access is required.

The default behavior remains unchanged (i.e. CPU access is assumed
unless otherwise specified). Clients like Chromium Embedded Framework
(CEF) or GPU only consumers can now specify
kPreferSharedImageWithNativeHandle to request buffers that are not CPU
accessible but support efficient GPU interop.

Bug: 428022619
Test:
FrameSinkVideoCapturerTest.BufferFormatPreferencePassedToGpuFramePool,
RenderableGpuMemoryBufferVideoFramePoolTest.RequiresCpuAccessAffectsBufferUsage

Change-Id: I7975173ed38300ce6fa995b530ada2c85a2cea27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6681354
Reviewed-by: Ted (Chromium) Meyer <tmathmeyer@chromium.org>
Commit-Queue: Anantanarayanan Iyengar US <aiyengar@nvidia.com>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1497315}