The necessary support for flipY is included in core Vulkan 1.1
so enable the feature if that's what's available.

Bug: angleproject:2968
Change-Id: I6808a1a0b1ace74976a7476f77d686e137a1e747
Reviewed-on: https://chromium-review.googlesource.com/c/1387758
Commit-Queue: Ian Elliott <ianelliott@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>