Make "--no-packages-dir" the default.

test/get/hosted/unlock_if_incompatible_test.dart

Index: test/get/hosted/unlock_if_incompatible_test.dart
diff --git a/test/get/hosted/unlock_if_incompatible_test.dart b/test/get/hosted/unlock_if_incompatible_test.dart
index 08d011c4e3f230dad61b315971efd19dab456fb2..7ecf0f5a323bc8d9e7d3907513a89b0d5dcfa7ce 100644
--- a/test/get/hosted/unlock_if_incompatible_test.dart
+++ b/test/get/hosted/unlock_if_incompatible_test.dart
@@ -14,12 +14,12 @@ main() {
 
     pubGet();
 
-    d.packagesDir({"foo": "1.0.0"}).validate();
+    d.appPackagesFile({"foo": "1.0.0"}).validate();
     globalPackageServer.add((builder) => builder.serve("foo", "1.0.1"));
     d.appDir({"foo": ">1.0.0"}).create();
 
     pubGet();
 
-    d.packagesDir({"foo": "1.0.1"}).validate();
+    d.appPackagesFile({"foo": "1.0.1"}).validate();
   });
 }