dart_pkg cleanups

services/dart/test/pingpong_target/BUILD.gn

Index: services/dart/test/pingpong_target/BUILD.gn
diff --git a/services/dart/test/pingpong_target/BUILD.gn b/services/dart/test/pingpong_target/BUILD.gn
index 848221d3c3fc02e062b71b9f308f79c5b46abe32..642a987b71217d351dedfe420303a165c9bf8cff 100644
--- a/services/dart/test/pingpong_target/BUILD.gn
+++ b/services/dart/test/pingpong_target/BUILD.gn
@@ -5,8 +5,10 @@
 import("//mojo/public/dart/rules.gni")
 
 dart_pkg("pingpong_target") {
-  apps = [ "lib/main.dart" ]
-  app_name_override = "dart_pingpong_target"
+  apps = [ [
+        "dart_pingpong_target",
+        "lib/main.dart",
+      ] ]
   sources = [
     "pubspec.yaml",
   ]