Revert "Add support for predictive back"

This reverts commit e1ed7f8ae7.

android/app/src/debug/AndroidManifest.xml

@@ -1,7 +1,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <application
         android:label="@string/app_name"
-        android:enableOnBackInvokedCallback="true"
     />
 
     <!-- The INTERNET permission is required for development. Specifically,

android/app/src/main/AndroidManifest.xml

@@ -2,8 +2,7 @@
     <application
         android:label="@string/app_name"
         android:name="${applicationName}"
-        android:icon="@mipmap/launcher_icon"
-        android:enableOnBackInvokedCallback="true">
+        android:icon="@mipmap/launcher_icon">
         <activity
             android:name=".MainActivity"
             android:exported="true"
@@ -12,7 +11,6 @@
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
-            android:enableOnBackInvokedCallback="true"
             android:windowSoftInputMode="adjustResize">
             <!-- Specifies an Android theme to apply to this Activity as soon as
                  the Android process has started. This theme is visible to the user

lib/models/themes/dark.dart

@@ -62,12 +62,6 @@ class DarkTheme extends AppTheme {
     return ThemeData(
       brightness: Brightness.dark,
       primarySwatch: createMaterialColor(AppTheme.mugitenWheat.background),
-      pageTransitionsTheme: const PageTransitionsTheme(
-        builders: {
-          // Use PredictiveBackPageTransitionsBuilder to get the predictive back route transition!
-          TargetPlatform.android: PredictiveBackPageTransitionsBuilder(),
-        },
-      ),
     );
   }
 }

lib/models/themes/light.dart

@@ -62,12 +62,6 @@ class LightTheme extends AppTheme {
       brightness: Brightness.light,
       primarySwatch: createMaterialColor(AppTheme.mugitenWheat.background),
       // primarySwatch: Colors.green,
-      pageTransitionsTheme: const PageTransitionsTheme(
-        builders: {
-          // Use PredictiveBackPageTransitionsBuilder to get the predictive back route transition!
-          TargetPlatform.android: PredictiveBackPageTransitionsBuilder(),
-        },
-      ),
     );
   }
 }