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

test/get/hosted/does_no_network_requests_when_possible_test.dart

Index: test/get/hosted/does_no_network_requests_when_possible_test.dart
diff --git a/test/get/hosted/does_no_network_requests_when_possible_test.dart b/test/get/hosted/does_no_network_requests_when_possible_test.dart
index 9330121ef7b3379cf8be596fed192bf5a87743d3..466fe3a72c7846b96757d195e315f1620c4f03c5 100644
--- a/test/get/hosted/does_no_network_requests_when_possible_test.dart
+++ b/test/get/hosted/does_no_network_requests_when_possible_test.dart
@@ -30,7 +30,7 @@ main() {
     pubGet();
 
     d.cacheDir({"foo": "1.2.0"}).validate();
-    d.packagesDir({"foo": "1.2.0"}).validate();
+    d.appPackagesFile({"foo": "1.2.0"}).validate();
 
     // The get should not have done any network requests since the lock file is
     // up to date.