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/libvulkan/libvulkan_flags.aconfig b/vulkan/libvulkan/libvulkan_flags.aconfig
new file mode 100644
index 0000000..891bc02
--- /dev/null
+++ b/vulkan/libvulkan/libvulkan_flags.aconfig
@@ -0,0 +1,10 @@
+package: "com.android.graphics.libvulkan.flags"
+container: "system"
+
+flag {
+  name: "swapchain_mutable_format_ext"
+  namespace: "core_graphics"
+  description: "Enable the VK_KHR_swapchain_mutable_format vulkan extension"
+  bug: "341978292"
+  is_fixed_read_only: true
+}