Fix nnbd/syntax/required_modifier_error_test

There were compilation errors reported because of missing default
values for non-required optional non-nullable parameters.

R=brianwilkerson@google.com, danrubel@google.com

Change-Id: If0454988219a7fece317c86124a81a2a8ce8bea4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/106963
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Dan Rubel <danrubel@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/tests/language_2/nnbd/syntax/required_modifier_error_test.dart b/tests/language_2/nnbd/syntax/required_modifier_error_test.dart
index b8265e3..059b2d5 100644
--- a/tests/language_2/nnbd/syntax/required_modifier_error_test.dart
+++ b/tests/language_2/nnbd/syntax/required_modifier_error_test.dart
@@ -29,12 +29,9 @@
 // Out of order modifiers
 class C2 {
   void m({
-    covariant
-    required //# 07: compile-time error
-    int i2,
-    final
-    required //# 08: compile-time error
-    int i3,
+    required int i1,
+    covariant required int i2, //# 07: compile-time error
+    final required int i3, //# 08: compile-time error
   }) {
   }
 }