[flutter_plugin_tools] Add a command to lint Android code (#4206)

Adds a new `lint-android` command to run `gradlew lint` on Android plugins.

Also standardizes the names of the Cirrus tasks that run all the build and platform-specific (i.e., not Dart unit test) tests for each platform, as they were getting unnecessarily long and complex in some cases.

Fixes https://github.com/flutter/flutter/issues/87071

script/tool/lib/src/lint_android_command.dart

@@ -0,0 +1,61 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:file/file.dart';
+import 'package:flutter_plugin_tools/src/common/plugin_utils.dart';
+import 'package:platform/platform.dart';
+
+import 'common/core.dart';
+import 'common/gradle.dart';
+import 'common/package_looping_command.dart';
+import 'common/process_runner.dart';
+
+/// Lint the CocoaPod podspecs and run unit tests.
+///
+/// See https://guides.cocoapods.org/terminal/commands.html#pod_lib_lint.
+class LintAndroidCommand extends PackageLoopingCommand {
+  /// Creates an instance of the linter command.
+  LintAndroidCommand(
+    Directory packagesDir, {
+    ProcessRunner processRunner = const ProcessRunner(),
+    Platform platform = const LocalPlatform(),
+  }) : super(packagesDir, processRunner: processRunner, platform: platform);
+
+  @override
+  final String name = 'lint-android';
+
+  @override
+  final String description = 'Runs "gradlew lint" on Android plugins.\n\n'
+      'Requires the example to have been build at least once before running.';
+
+  @override
+  Future<PackageResult> runForPackage(Directory package) async {
+    if (!pluginSupportsPlatform(kPlatformAndroid, package,
+        requiredMode: PlatformSupport.inline)) {
+      return PackageResult.skip(
+          'Plugin does not have an Android implemenatation.');
+    }
+
+    final Directory exampleDirectory = package.childDirectory('example');
+    final GradleProject project = GradleProject(exampleDirectory,
+        processRunner: processRunner, platform: platform);
+
+    if (!project.isConfigured()) {
+      return PackageResult.fail(<String>['Build example before linting']);
+    }
+
+    final String packageName = package.basename;
+
+    // Only lint one build mode to avoid extra work.
+    // Only lint the plugin project itself, to avoid failing due to errors in
+    // dependencies.
+    //
+    // TODO(stuartmorgan): Consider adding an XML parser to read and summarize
+    // all results. Currently, only the first three errors will be shown inline,
+    // and the rest have to be checked via the CI-uploaded artifact.
+    final int exitCode = await project.runCommand('$packageName:lintDebug');
+
+    return exitCode == 0 ? PackageResult.success() : PackageResult.fail();
+  }
+}