Vulkan: Drop support for VMA 2.0 Since ANGLE and Chromium were last updated to use VMA 3.0, there have been no breaking issues so far. * ANGLE update: https://crrev.com/c/4777337 * Chromium update: https://crrev.com/c/4911597 Therefore, the support for the old VMA (2.3) can now be removed. * Removed ANGLE_VMA_VERSION from the build files, since they are no longer required. * Removed the VMA-related guards in the code as well. * Removed the flags and thresholds for the buddy algorithm, which were used in VMA 2.3. * Share group buffer pools is no longer a map. Bug: b/303290680 Change-Id: Ic2b29e8f95ca5c941b297b20442c5bad4b8f52e3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4791667 Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>