Set VkApplicationInfo.pEngineName to DAWN

Setting the pEngineName helps with the collection of metrics and is
generally good practice.

Bug: n/a
Change-Id: I14496826fd960d2219f0378f47e345ddd5241629
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/176160
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Loko Kung <lokokung@google.com>
Commit-Queue: Austin Eng <enga@chromium.org>
diff --git a/src/dawn/native/vulkan/BackendVk.cpp b/src/dawn/native/vulkan/BackendVk.cpp
index fabed04..4dd3597 100644
--- a/src/dawn/native/vulkan/BackendVk.cpp
+++ b/src/dawn/native/vulkan/BackendVk.cpp
@@ -463,7 +463,7 @@
     appInfo.pNext = nullptr;
     appInfo.pApplicationName = nullptr;
     appInfo.applicationVersion = 0;
-    appInfo.pEngineName = nullptr;
+    appInfo.pEngineName = "Dawn";
     appInfo.engineVersion = 0;
     appInfo.apiVersion = std::min(mGlobalInfo.apiVersion, VK_API_VERSION_1_3);