Avoid ANGLE formats on dmabuf-backed EGL images DrmFourCCFormatToGLInternalFormat can return ANGLE-internal formats that are only used on the Vulkan backend. This CL adds special logic to dmabuf-backed EGL images to convert those formats back to GL_RGB8. Bug: chromium:1353374 Change-Id: Id270d3d47d289620730c522d2e29d7fc67dc8321 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3911355 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Brian Ho <hob@chromium.org>