Vulkan: Enable 16bpp texture tests Possibly fixed in 6c6be2cef6c1a8d7a37712aa36d2ef5a1c3990c0. Bug: angleproject:2649 Bug: angleproject:2656 Change-Id: I0ab97e2d828b6b8643a68ab9b28fc0ccd8f08c48 Reviewed-on: https://chromium-review.googlesource.com/c/1289350 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>