Vulkan: Enable VK_KHR_get_memory_requirements2 extension 1. Don't assume support for VK_KHR_get_memory_requirements2. Enable the extension, if supported, during device creation. 2. Also let VMA fill in the function pointers for these commands based on Vulkan API version - 1. vkGetBufferMemoryRequirements2KHR 2. vkGetImageMemoryRequirements2KHR Bug: angleproject:4830 Change-Id: Icd0b3baf56732b5f5f49f320c1feb996204169ed Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2293633 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Mohan Maiya <m.maiya@samsung.com>