Introduce TabBar.indicatorAnimation to customize tab indicator animation (#151746)

fixes [Add ability to customize `TabBar` indicator animation](https://github.com/flutter/flutter/issues/150508)

Similar option exist on Android
https://developer.android.com/reference/com/google/android/material/tabs/TabLayout#setTabIndicatorAnimationMode(int)

### Dartpad Example Preview
<img width="874" alt="Screenshot 2024-07-12 at 17 36 08" src="https://github.com/user-attachments/assets/e349c5aa-ee5d-46ce-9e44-4f02346603bd">

### Linear vs Elastic tab indicator animation

https://github.com/user-attachments/assets/d7ae3ae4-ae52-4ccd-89b1-75908bf8a34d

examples/api/lib/material/tabs/tab_bar.indicator_animation.0.dart

@@ -0,0 +1,106 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+
+/// Flutter code sample for [TabBar.indicatorAnimation].
+
+void main() => runApp(const IndicatorAnimationExampleApp());
+
+class IndicatorAnimationExampleApp extends StatelessWidget {
+  const IndicatorAnimationExampleApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const MaterialApp(
+      home: IndicatorAnimationExample(),
+    );
+  }
+}
+
+const List<(TabIndicatorAnimation, String)> indicatorAnimationSegments = <(TabIndicatorAnimation, String)>[
+  (TabIndicatorAnimation.linear, 'Linear'),
+  (TabIndicatorAnimation.elastic, 'Elastic'),
+];
+
+class IndicatorAnimationExample extends StatefulWidget {
+  const IndicatorAnimationExample({super.key});
+
+  @override
+  State<IndicatorAnimationExample> createState() => _IndicatorAnimationExampleState();
+}
+
+class _IndicatorAnimationExampleState extends State<IndicatorAnimationExample> {
+  Set<TabIndicatorAnimation> _animationStyleSelection = <TabIndicatorAnimation>{TabIndicatorAnimation.linear};
+  TabIndicatorAnimation _tabIndicatorAnimation = TabIndicatorAnimation.linear;
+
+  @override
+  Widget build(BuildContext context) {
+    return DefaultTabController(
+      length: 6,
+      child: Scaffold(
+        appBar: AppBar(
+          title: const Text('Indicator Animation Example'),
+          bottom: TabBar(
+            indicatorAnimation: _tabIndicatorAnimation,
+            isScrollable: true,
+            tabAlignment: TabAlignment.start,
+            tabs: const <Widget>[
+              Tab(text: 'Short Tab'),
+              Tab(text: 'Very Very Very Long Tab'),
+              Tab(text: 'Short Tab'),
+              Tab(text: 'Very Very Very Long Tab'),
+              Tab(text: 'Short Tab'),
+              Tab(text: 'Very Very Very Long Tab'),
+            ],
+          ),
+        ),
+        body: Column(
+          children: <Widget>[
+            const SizedBox(height: 16),
+            SegmentedButton<TabIndicatorAnimation>(
+              selected: _animationStyleSelection,
+              onSelectionChanged: (Set<TabIndicatorAnimation> styles) {
+                setState(() {
+                  _animationStyleSelection = styles;
+                  _tabIndicatorAnimation = styles.first;
+                });
+              },
+             segments: indicatorAnimationSegments
+               .map<ButtonSegment<TabIndicatorAnimation>>(((TabIndicatorAnimation, String) shirt) {
+                 return ButtonSegment<TabIndicatorAnimation>(value: shirt.$1, label: Text(shirt.$2));
+               })
+               .toList(),
+            ),
+            const SizedBox(height: 16),
+            const Expanded(
+              child: TabBarView(
+                children: <Widget>[
+                  Center(
+                    child: Text('Short Tab Page'),
+                  ),
+                  Center(
+                    child: Text('Very Very Very Long Tab Page'),
+                  ),
+                  Center(
+                    child: Text('Short Tab Page'),
+                  ),
+                  Center(
+                    child: Text('Very Very Very Long Tab Page'),
+                  ),
+                  Center(
+                    child: Text('Short Tab Page'),
+                  ),
+                  Center(
+                    child: Text('Very Very Very Long Tab Page'),
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

examples/api/test/material/tabs/tab_bar.indicator_animation.0_test.dart

@@ -0,0 +1,85 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:flutter_api_samples/material/tabs/tab_bar.indicator_animation.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('TabBar.indicatorAnimation can customize tab indicator animation', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.IndicatorAnimationExampleApp(),
+    );
+
+    final RenderBox tabBarBox = tester.firstRenderObject<RenderBox>(find.byType(TabBar));
+
+    late RRect indicatorRRect;
+
+    expect(tabBarBox, paints..something((Symbol method, List<dynamic> arguments) {
+      if (method != #drawRRect) {
+        return false;
+      }
+      indicatorRRect = arguments[0] as RRect;
+      return true;
+    }));
+    expect(indicatorRRect.left, equals(16.0));
+    expect(indicatorRRect.top, equals(45.0));
+    expect(indicatorRRect.right, closeTo(142.9, 0.1));
+    expect(indicatorRRect.bottom, equals(48.0));
+
+    // Tap the long tab.
+    await tester.tap(find.text('Very Very Very Long Tab').first);
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(tabBarBox, paints..something((Symbol method, List<dynamic> arguments) {
+      if (method != #drawRRect) {
+        return false;
+      }
+      indicatorRRect = arguments[0] as RRect;
+      return true;
+    }));
+    expect(indicatorRRect.left, closeTo(107.5, 0.1));
+    expect(indicatorRRect.top, equals(45.0));
+    expect(indicatorRRect.right, closeTo(348.2, 0.1));
+    expect(indicatorRRect.bottom, equals(48.0));
+
+    // Tap to go to the first tab.
+    await tester.tap(find.text('Short Tab').first);
+    await tester.pumpAndSettle();
+
+    expect(tabBarBox, paints..something((Symbol method, List<dynamic> arguments) {
+      if (method != #drawRRect) {
+        return false;
+      }
+      indicatorRRect = arguments[0] as RRect;
+      return true;
+    }));
+    expect(indicatorRRect.left, equals(16.0));
+    expect(indicatorRRect.top, equals(45.0));
+    expect(indicatorRRect.right, closeTo(142.9, 0.1));
+    expect(indicatorRRect.bottom, equals(48.0));
+
+    // Select the elastic animation.
+    await tester.tap(find.text('Elastic'));
+    await tester.pumpAndSettle();
+
+    // Tap the long tab.
+    await tester.tap(find.text('Very Very Very Long Tab').first);
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(tabBarBox, paints..something((Symbol method, List<dynamic> arguments) {
+      if (method != #drawRRect) {
+        return false;
+      }
+      indicatorRRect = arguments[0] as RRect;
+      return true;
+    }));
+    expect(indicatorRRect.left, closeTo(51.0, 0.1));
+    expect(indicatorRRect.top, equals(45.0));
+    expect(indicatorRRect.right, closeTo(221.4, 0.1));
+    expect(indicatorRRect.bottom, equals(48.0));
+  });
+}