Migrate cocoapods_test.dart to explicit-package-dependencies. (#160264)

Work towards flutter/flutter#160257.

Author: matanlurey

packages/flutter_tools/test/general.shard/macos/cocoapods_test.dart

@@ -9,6 +9,7 @@ import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/base/version.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/cache.dart';
+import 'package:flutter_tools/src/dart/pub.dart';
 import 'package:flutter_tools/src/features.dart';
 import 'package:flutter_tools/src/flutter_plugins.dart';
 import 'package:flutter_tools/src/ios/xcodeproj.dart';
@@ -21,6 +22,7 @@ import 'package:unified_analytics/unified_analytics.dart';
 import '../../src/common.dart';
 import '../../src/context.dart';
 import '../../src/fake_process_manager.dart';
+import '../../src/fake_pub_deps.dart';
 import '../../src/fakes.dart';
 
 enum _StdioStream {
@@ -36,6 +38,12 @@ void main() {
   late TestUsage usage;
   late FakeAnalytics fakeAnalytics;
 
+  // TODO(matanlurey): Remove after `explicit-package-dependencies` is enabled by default.
+  // See https://github.com/flutter/flutter/issues/160257 for details.
+  FeatureFlags enableExplicitPackageDependencies() {
+    return TestFeatureFlags(isExplicitPackageDependenciesEnabled: true);
+  }
+
   void pretendPodVersionFails() {
     fakeProcessManager.addCommand(
       const FakeCommand(
@@ -358,6 +366,8 @@ void main() {
     }, overrides: <Type, Generator>{
       FileSystem: () => fileSystem,
       ProcessManager: () => FakeProcessManager.any(),
+      FeatureFlags: enableExplicitPackageDependencies,
+      Pub: FakePubWithPrimedDeps.new,
     });
   });