Vulkan: Move Feature init before device creation. We were previously creating our device *before* initializing the FeaturesVk fields. This means we weren't requesting the MAINTENANCE1 extension correctly. Moving feature init before the first createDevice call fixes the ordering issue. This unblocks the viewport flip behaviour fixes. Bug: angleproject:2673 Change-Id: Iae6973b57bcb4da78134a17b0644cd248bfb4981 Reviewed-on: https://chromium-review.googlesource.com/1133920 Reviewed-by: Luc Ferron <lucferron@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>