Fix the length of the valueHelp on the --sample option for the create command,...

Fix the length of the valueHelp on the --sample option for the create command, and turn on wrapping. (#28264)

The wrapping for some commands was never actually turned on, so this turns it on.

Also, it shortens the `valueHelp` for the `--sample` option to be just "id" instead of "the sample ID of the desired sample from the API documentation website (http://docs.flutter.io)", which was causing the line to get far too long.

Fixes #23074

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

@@ -90,9 +90,10 @@ class CreateCommand extends FlutterCommand {
       'sample',
       abbr: 's',
       help: 'Specifies the Flutter code sample to use as the main.dart for an application. Implies '
-        '--template=app.',
+        '--template=app. The value should be the sample ID of the desired sample from the API '
+        'documentation website (http://docs.flutter.io).',
       defaultsTo: null,
-      valueHelp: 'the sample ID of the desired sample from the API documentation website (http://docs.flutter.io)'
+      valueHelp: 'id',
     );
     argParser.addFlag(
       'overwrite',

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -13,6 +13,7 @@ import '../application_package.dart';
 import '../base/common.dart';
 import '../base/context.dart';
 import '../base/file_system.dart';
+import '../base/terminal.dart';
 import '../base/time.dart';
 import '../base/user_messages.dart';
 import '../base/utils.dart';
@@ -82,7 +83,10 @@ abstract class FlutterCommand extends Command<void> {
 
   @override
   ArgParser get argParser => _argParser;
-  final ArgParser _argParser = ArgParser(allowTrailingOptions: false);
+  final ArgParser _argParser = ArgParser(
+    allowTrailingOptions: false,
+    usageLineLength: outputPreferences.wrapText ? outputPreferences.wrapColumn : null,
+  );
 
   @override
   FlutterCommandRunner get runner => super.runner;