PbufferSurfaces are now created with VK_KHR_image_format_list extension support enabled. Bug: angleproject:2514 Bug: angleproject:5281 Test: PbufferTest.ClearAndBindTexImageSrgb*Vulkan Change-Id: I8977484c958328d00f688faa7adffff85a37a3b8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2530535 Commit-Queue: Mohan Maiya <m.maiya@samsung.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>
