Updated custom ListTile examples (#128071)

examples/api/lib/material/list_tile/custom_list_item.1.dart

@@ -13,8 +13,9 @@ class CustomListItemApp extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return const MaterialApp(
-      home: CustomListItemExample(),
+    return MaterialApp(
+      theme: ThemeData(useMaterial3: true),
+      home: const CustomListItemExample(),
     );
   }
 }
@@ -37,10 +38,6 @@ class _ArticleDescription extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Column(
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: <Widget>[
-        Expanded(
-          child: Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: <Widget>[
         Text(
@@ -52,7 +49,8 @@ class _ArticleDescription extends StatelessWidget {
           ),
         ),
         const Padding(padding: EdgeInsets.only(bottom: 2.0)),
-              Text(
+        Expanded(
+          child: Text(
             subtitle,
             maxLines: 2,
             overflow: TextOverflow.ellipsis,
@@ -61,14 +59,7 @@ class _ArticleDescription extends StatelessWidget {
               color: Colors.black54,
             ),
           ),
-            ],
-          ),
         ),
-        Expanded(
-          child: Column(
-            crossAxisAlignment: CrossAxisAlignment.start,
-            mainAxisAlignment: MainAxisAlignment.end,
-            children: <Widget>[
         Text(
           author,
           style: const TextStyle(
@@ -84,9 +75,6 @@ class _ArticleDescription extends StatelessWidget {
           ),
         ),
       ],
-          ),
-        ),
-      ],
     );
   }
 }

examples/api/test/material/list_tile/custom_list_item.1_test.dart

@@ -20,7 +20,7 @@ void main() {
     expect(thumbnailAspectRatio.aspectRatio, 1.0);
 
     // The Expanded widget is used to control the size of the text.
-    Expanded textExpanded = tester.widget(find.ancestor(
+    final Expanded textExpanded = tester.widget(find.ancestor(
       of: find.text('Flutter 1.0 Launch'),
       matching: find.byType(Expanded).at(0),
     ));
@@ -32,12 +32,5 @@ void main() {
       matching: find.byType(AspectRatio),
     ));
     expect(thumbnailAspectRatio.aspectRatio, 1.0);
-
-    // The Expanded widget is used to control the size of the text.
-    textExpanded = tester.widget(find.ancestor(
-      of: find.text('Flutter 1.2 Release - Continual updates to the framework'),
-      matching: find.byType(Expanded).at(3),
-    ));
-    expect(textExpanded.flex, 1);
   });
 }

packages/flutter/lib/src/material/list_tile.dart

@@ -296,8 +296,6 @@ enum ListTileTitleAlignment {
 /// Here is an example of a custom list item that resembles a YouTube-related
 /// video list item created with [Expanded] and [Container] widgets.
 ///
-/// ![Custom list item a](https://flutter.github.io/assets-for-api-docs/assets/widgets/custom_list_item_a.png)
-///
 /// ** See code in examples/api/lib/material/list_tile/custom_list_item.0.dart **
 /// {@end-tool}
 ///
@@ -306,8 +304,6 @@ enum ListTileTitleAlignment {
 /// subtitles. It utilizes [Row]s and [Column]s, as well as [Expanded] and
 /// [AspectRatio] widgets to organize its layout.
 ///
-/// ![Custom list item b](https://flutter.github.io/assets-for-api-docs/assets/widgets/custom_list_item_b.png)
-///
 /// ** See code in examples/api/lib/material/list_tile/custom_list_item.1.dart **
 /// {@end-tool}
 ///