fix Android example app

example/android/app/build.gradle

@@ -29,7 +29,7 @@ apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
     compileSdkVersion 31
-    ndkVersion "23.1.7779620"
+    ndkVersion "25.2.9519653"
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -45,12 +45,14 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "app.polyvox.filament_example"
-        minSdkVersion 21
-        targetSdkVersion 30
+        minSdkVersion 22
+        targetSdkVersion 31
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
+        ndk {
+            abiFilters 'arm64-v8a' // 'x86_64' 'armeabi-v7a' 
+        }
     }
 
     buildTypes {
@@ -63,12 +65,6 @@ android {
                     'proguard-rules.pro'
         }
     }
-    packagingOptions {
-        pickFirst "lib/**/libjnidispatch.so"
-    }
-    aaptOptions {
-      noCompress "ktx"
-    }
 }
 
 flutter {

example/android/app/src/main/AndroidManifest.xml

@@ -12,7 +12,8 @@
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
-            android:windowSoftInputMode="adjustResize">
+            android:windowSoftInputMode="adjustResize"
+            android:exported="true">
             <!-- Specifies an Android theme to apply to this Activity as soon as
                  the Android process has started. This theme is visible to the user
                  while the Flutter UI initializes. After that, this theme continues

example/android/app/src/main/kotlin/app/polyvox/example/MainActivity.kt

@@ -0,0 +1,6 @@
+package app.polyvox.example
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity: FlutterActivity() {
+}