[automerger skipped] Use upstream Vulkan headers from external/vulkan-headers
am: c6882b4814 -s ours
am skip reason: change_id If4677d08a6891b18ce347e3fa3be393fc6111fc8 with SHA1 b9d7b81a3b is in history

Change-Id: Ia7cb1f90dc185b4dbdda78b2504da4c7eac1e989