[ez][ET-VK] Update Vulkan runtime application name (#16187)

Stack from [ghstack](https://github.com/ezyang/ghstack) (oldest at
bottom):
* __->__ #16187
* #16186

TSIA!

Differential Revision:
[D88802100](https://our.internmc.facebook.com/intern/diff/D88802100/)

cc @manuelcandales @digantdesai @cbilgin

---------

Co-authored-by: ssjia <ssjia@devvm1479.ncg0.facebook.com>

Author: SS-JIA

backends/vulkan/runtime/vk_api/Runtime.cpp

@@ -82,7 +82,7 @@ VkInstance create_instance(const RuntimeConfig& config) {
   const VkApplicationInfo application_info{
       VK_STRUCTURE_TYPE_APPLICATION_INFO, // sType
       nullptr, // pNext
-      "PyTorch Vulkan Backend", // pApplicationName
+      "ExecuTorch Vulkan Delegate", // pApplicationName
       0, // applicationVersion
       nullptr, // pEngineName
       0, // engineVersion