Merge "libvulkan: ensure layer discovery is triggered only once for a new process"

    });

    {

        static pid_t pid = getpid() + 1;

        static std::mutex layer_lock;

        std::lock_guard<std::mutex> lock(layer_lock);

        if (pid != getpid()) {

            pid = getpid();

            DiscoverLayers();

        }

    }

    return initialized;

}