Implement the VK_KHR_swapchain_mutable_format device extension in the vulkan loader

Add an implementation for the VK_KHR_swapchain_mutable_format extension.

Test: Stepped through changes in debugger
Test: Ran sample app with VVL which used the extension
Test: Ran dEQP-VK.image.swapchain_mutable.android.* dEQP tests
Flag: com.android.graphics.libvulkan.flags.swapchain_mutable_format_ext
Bug: 341978292
Change-Id: Ib0e5b9f750cd5a94ab65419542898db207716fcc
diff --git a/vulkan/scripts/null_generator.py b/vulkan/scripts/null_generator.py
index 3624c1d..5c5bea3 100644
--- a/vulkan/scripts/null_generator.py
+++ b/vulkan/scripts/null_generator.py
@@ -55,6 +55,9 @@
 #include <vulkan/vk_android_native_buffer.h>
 #include <vulkan/vulkan.h>
 
+/*
+ * This file is autogenerated by null_generator.py. Do not edit directly.
+ */
 namespace null_driver {
 
 PFN_vkVoidFunction GetGlobalProcAddr(const char* name);
@@ -97,6 +100,9 @@
 
 using namespace null_driver;
 
+/*
+ * This file is autogenerated by null_generator.py. Do not edit directly.
+ */
 namespace {
 
 struct NameProc {