Do not cleanup Gradle in non-Android integration tests (#66487)

dev/devicelab/lib/framework/runner.dart

@@ -10,7 +10,7 @@ import 'package:path/path.dart' as path;
 import 'package:vm_service_client/vm_service_client.dart';
 
 import 'package:flutter_devicelab/framework/utils.dart';
-import 'package:flutter_devicelab/framework/adb.dart' show DeviceIdEnvName;
+import 'package:flutter_devicelab/framework/adb.dart';
 
 /// Runs a task in a separate Dart VM and collects the result using the VM
 /// service protocol.
@@ -123,6 +123,7 @@ Future<VMIsolateRef> _connectToRunnerIsolate(Uri vmServiceUri) async {
 }
 
 Future<void> cleanupSystem() async {
+  if (deviceOperatingSystem == null || deviceOperatingSystem == DeviceOperatingSystem.android) {
     print('\n\nCleaning up system after task...');
     final String javaHome = await findJavaHome();
     if (javaHome != null) {
@@ -148,7 +149,7 @@ Future<void> cleanupSystem() async {
       await exec(
         path.join(tempDir.path, gradlewBinaryName),
         <String>['--stop'],
-      environment: <String, String>{ 'JAVA_HOME': javaHome },
+        environment: <String, String>{ 'JAVA_HOME': javaHome},
         workingDirectory: tempDir.path,
         canFail: true,
       );
@@ -162,4 +163,5 @@ Future<void> cleanupSystem() async {
     // next devicelab task to fail.
     // https://github.com/flutter/flutter/issues/65277
     rmTree(dir('${Platform.environment['HOME']}/.gradle'));
+  }
 }