Roll (1/2) LVL version forward and disable VANGLE Bug: angleproject:2482 Rolling Vulkan validation code forward to HEAD of master as of 4/18/18 morning. Disable Vulkan from the ANGLE build until ANGLE lands in Chromium. After that second part of roll will be submitted. This LVL update includes reg.py script fixes for a number of build warnings as well as a validation fix for vkCmdClearAttachments() in secondary cmd buffer. Change-Id: I7f8100f5b656d86caf8f4b5dee61a733a35b7869 Reviewed-on: https://chromium-review.googlesource.com/1016860 Reviewed-by: Jamie Madill <jmadill@chromium.org>