This triggers vk::DynamicBuffer allocations in BufferVk.

Bug: angleproject:5719
Change-Id: Ida855b23618497f76102e55f89ab1678f9c08753
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2809856Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>