Fix a bunch of pub tests that started running "pub get".

test/dart2js/supports_valid_options_test.dart

Index: test/dart2js/supports_valid_options_test.dart
diff --git a/test/dart2js/supports_valid_options_test.dart b/test/dart2js/supports_valid_options_test.dart
index 17fb66d389b0535494da6dbe4b03ff1e3d838b57..ec02f4dd19cff2d88b1dc7e5bb7ed70d5968561c 100644
--- a/test/dart2js/supports_valid_options_test.dart
+++ b/test/dart2js/supports_valid_options_test.dart
@@ -35,7 +35,7 @@ main() {
     ]).create();
 
     // None of these options should be rejected, either by pub or by dart2js.
-    pubServe();
+    pubServe(shouldGetFirst: true);
     requestShouldSucceed("main.dart.js", isNot(isEmpty));
     endPubServe();
   });