win ninja: default to embedding manifest to match msvs

test/win/linker-flags/generate-manifest.gyp

Index: test/win/linker-flags/generate-manifest.gyp
diff --git a/test/win/linker-flags/generate-manifest.gyp b/test/win/linker-flags/generate-manifest.gyp
index 41f888fafb546f98c9c7d1c5e3c240bc140f21ea..34a68d1a489db79de2fd90c43eb902df06f945b1 100644
--- a/test/win/linker-flags/generate-manifest.gyp
+++ b/test/win/linker-flags/generate-manifest.gyp
@@ -152,5 +152,15 @@
         },
       },
     },
+    {
+      'target_name': 'test_generate_manifest_default_embed_default',
+      'type': 'executable',
+      'sources': ['hello.cc'],
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'EnableUAC': 'true',
+        },
+      },
+    },
   ]
 }