Remove "unnecessary" imports. (#77559)

packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart

diff --git a/packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart b/packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart
index 4b772fb..ff1661f 100644
--- a/packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart
+++ b/packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart
@@ -4,8 +4,6 @@
 
 // @dart = 2.8
 
-import 'dart:io';
-
 import 'package:args/command_runner.dart';
 import 'package:flutter_tools/src/android/android_builder.dart';
 import 'package:flutter_tools/src/android/android_sdk.dart';