Much like XlibSurfaceKHR, doesn't cope with any formats aside from 24-bit RGB.

Bug: b/124265819
Bug: b/139412276
Bug: b/139491466
Change-Id: I1146f6ff672a9016be04e6b4d595de40fa03346f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/35149
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>