Add deprecation warning for "flutter create --ios-language" (#155867)

The Objective-C  `flutter create --ios-language objc` template will be removed in flutter/flutter#148586.

Add a deprecation warning when this flag is passed.  Add an additional warning when Objective-C is specified requesting the user's use-case.

Do not show the warning when creating the module, as Swift is not supported for it yet flutter/flutter#23955

![Screenshot 2024-09-27 at 8 54 16�PM](https://github.com/user-attachments/assets/112be47f-a5bd-4f57-9a9d-c96c7bbc8ac3)

Part of flutter/flutter#148586

Author: jmagman

packages/flutter_tools/lib/src/commands/create.dart

@@ -258,6 +258,13 @@ class CreateCommand extends CreateBase {
         'template: the language will always be C or C++.',
         exitCode: 2,
       );
+    } else if (argResults!.wasParsed('ios-language')) {
+      globals.printWarning(
+          'The "ios-language" option is deprecated and will be removed in a future Flutter release.');
+      if (stringArg('ios-language') == 'objc') {
+        globals.printWarning(
+            'Please comment in https://github.com/flutter/flutter/issues/148586 describing your use-case for using Objective-C instead of Swift.');
+      }
     }
 
     final String organization = await getOrganization();

packages/flutter_tools/lib/src/commands/create_base.dart

@@ -100,14 +100,15 @@ abstract class CreateBase extends FlutterCommand {
       abbr: 'i',
       defaultsTo: 'swift',
       allowed: <String>['objc', 'swift'],
-      help: 'The language to use for iOS-specific code, either Objective-C (legacy) or Swift (recommended).'
+      help: '(deprecated) The language to use for iOS-specific code, either Swift (recommended) or Objective-C (legacy).',
+      hide: !verboseHelp,
     );
     argParser.addOption(
       'android-language',
       abbr: 'a',
       defaultsTo: 'kotlin',
       allowed: <String>['java', 'kotlin'],
-      help: 'The language to use for Android-specific code, either Java (legacy) or Kotlin (recommended).',
+      help: 'The language to use for Android-specific code, either Kotlin (recommended) or Java (legacy).',
     );
     argParser.addFlag(
       'skip-name-checks',

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

@@ -1686,6 +1686,36 @@ void main() {
     expect(displayName, 'My Project');
   });
 
+  testUsingContext('should not show --ios-language deprecation warning issue for Swift', () async {
+    Cache.flutterRoot = '../..';
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--ios-language=swift', projectDir.path]);
+    expect(logger.warningText, contains('The "ios-language" option is deprecated and will be removed in a future Flutter release.'));
+    expect(logger.warningText, isNot(contains('https://github.com/flutter/flutter/issues/148586')));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
+  testUsingContext('should show --ios-language deprecation warning issue for Objective-C', () async {
+    Cache.flutterRoot = '../..';
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--ios-language=objc', projectDir.path]);
+    expect(logger.warningText, contains('The "ios-language" option is deprecated and will be removed in a future Flutter release.'));
+    expect(logger.warningText, contains('https://github.com/flutter/flutter/issues/148586'));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
   testUsingContext('has correct content and formatting with macOS app template', () async {
     Cache.flutterRoot = '../..';