[RESTRICT AUTOMERGE] libvulkan: drop the advertised swapchain spec version to 68

            memcpy(prop.extensionName, VK_KHR_SWAPCHAIN_EXTENSION_NAME,

                   sizeof(VK_KHR_SWAPCHAIN_EXTENSION_NAME));

            prop.specVersion = VK_KHR_SWAPCHAIN_SPEC_VERSION;

            // b/130182551 VK_KHR_SWAPCHAIN_SPEC_VERSION > 68 has structs the

            // loader doesn't handle properly. So drop the spec version to 68.

            prop.specVersion = 68;

        }

    }