Vulkan: Fix all copyTexImage/copySubTexImage cases with Y flip - Validated by running: -functional_texture_specification_basic_copytexsubimage2d_* -functional_texture_specification_basic_copyteximage2d_* With the flip flag enabled. Bug: angleproject:2673 Change-Id: I5a3041af79f9316256b0650ab7e3fd0e086e46e3 Reviewed-on: https://chromium-review.googlesource.com/1129820 Commit-Queue: Luc Ferron <lucferron@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>