Fixed AlertDialog Height of example in image_picker (flutter#4800)

**Issue**
![Issue](https://github.com/flutter/packages/assets/61612013/e7994142-fa16-4934-8d6d-29ee825a7853)
**Fixed**
![Fixed](https://github.com/flutter/packages/assets/61612013/812078ba-8eec-48d7-aac7-0c7381ae0473)

Author: AnujPandey007

packages/image_picker/image_picker/example/lib/main.dart

@@ -465,6 +465,7 @@ class _MyHomePageState extends State<MyHomePage> {
           return AlertDialog(
             title: const Text('Add optional parameters'),
             content: Column(
+              mainAxisSize: MainAxisSize.min,
               children: <Widget>[
                 TextField(
                   controller: maxWidthController,