[embedder] Fix getting vkGetInstanceProcAddr (#39051)

Author: nanokatze

shell/platform/embedder/embedder.cc

@@ -562,7 +562,7 @@ InferVulkanPlatformViewCreationCallback(
 
   auto vk_instance = static_cast<VkInstance>(config->vulkan.instance);
   auto proc_addr =
-      vulkan_get_instance_proc_address(vk_instance, "GetInstanceProcAddr");
+      vulkan_get_instance_proc_address(vk_instance, "vkGetInstanceProcAddr");
 
   flutter::EmbedderSurfaceVulkan::VulkanDispatchTable vulkan_dispatch_table = {
       .get_instance_proc_address =

shell/platform/embedder/tests/embedder_config_builder.cc

@@ -513,7 +513,8 @@ void EmbedderConfigBuilder::InitializeVulkanRendererConfig() {
       [](void* context, FlutterVulkanInstanceHandle instance,
          const char* name) -> void* {
     auto proc_addr = reinterpret_cast<EmbedderTestContextVulkan*>(context)
-                         ->vulkan_context_->vk_->GetInstanceProcAddr;
+                         ->vulkan_context_->vk_->GetInstanceProcAddr(
+                             reinterpret_cast<VkInstance>(instance), name);
     return reinterpret_cast<void*>(proc_addr);
   };
   vulkan_renderer_config_.get_next_image_callback =