add predictive back gesture

android/app/src/main/AndroidManifest.xml

@@ -3,7 +3,8 @@
     <application
         android:label="OpenStore"
         android:name="${applicationName}"
-        android:icon="@mipmap/ic_launcher">
+        android:icon="@mipmap/ic_launcher"
+        android:enableOnBackInvokedCallback="true">
         <activity
             android:name=".MainActivity"
             android:exported="true"

lib/main.dart

@@ -41,6 +41,9 @@ class MyApp extends StatelessWidget {
     return MaterialApp.router(
       title: 'OpenStore',
       theme: ThemeData(
+        pageTransitionsTheme: const PageTransitionsTheme(builders: {
+          TargetPlatform.android: PredictiveBackPageTransitionsBuilder(),
+        }),
         colorScheme: ColorScheme.fromSeed(
           seedColor: Colors.blue,
           brightness: Brightness.dark,