My Moto G4 plus just got the nougat update and Vulkan with it.(I checked in /system/lib too,its there.)
The Vulkan driver crashes just like on a device without Vulkan.(RetroArch says “Vulkan support:yes” in info)
I would fix this myself but I don’t use graphics librarys.(Never have,I always use framebuffer for graphics since those library’s make no since to me.)