Update LSP noEdits test to have imports that won't be removed as unused

Change-Id: I6e9d1111e4c9bcb37ad8722d175f3b78b9d8f842
Reviewed-on: https://dart-review.googlesource.com/c/86930
Commit-Queue: Danny Tuppeny <dantup@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Auto-Submit: Danny Tuppeny <dantup@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analysis_server/test/lsp/code_actions_source_test.dart b/pkg/analysis_server/test/lsp/code_actions_source_test.dart
index aa1e445..a1f9cfb 100644
--- a/pkg/analysis_server/test/lsp/code_actions_source_test.dart
+++ b/pkg/analysis_server/test/lsp/code_actions_source_test.dart
@@ -181,7 +181,10 @@
   test_noEdits() async {
     const content = '''
 import 'dart:async';
-import 'dart:convert';
+import 'dart:math';
+
+Future foo;
+int minified(int x, int y) => min(x, y);
     ''';
     await newFile(mainFilePath, content: content);
     await initialize();