Fix import pattern (#140425)

This PR is just to fix the import pattern to follow the convention.

packages/flutter/lib/src/material/search_bar_theme.dart

@@ -6,9 +6,9 @@ import 'dart:ui' show lerpDouble;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
-import '../../services.dart';
 import 'material_state.dart';
 import 'theme.dart';