Vulkan: Support non-pow2 buffer alignments Bug: angleproject:2898 Change-Id: I7c8e548a1a449f48225516c37d830ecc201b064d Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1762496 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>