Flutter demos: use flutter.ndkVersion again #127

Testing with Flutter 3.29+ and the NDK version was updated with 3.27
already.

Author: greenrobot-team

objectbox/example/flutter/objectbox_demo/android/app/build.gradle

@@ -25,13 +25,7 @@ if (flutterVersionName == null) {
 android {
     namespace "com.example.objectbox_demo"
     compileSdkVersion flutter.compileSdkVersion
-    // ObjectBox: Flutter defaults to NDK 23.1.7779620, but
-    // - objectbox_flutter_libs requires Android NDK 25.1.8937393
-    // - path_provider_android requires Android NDK 25.1.8937393
-    // Until Flutter uses a newer version (https://github.com/flutter/flutter/commit/919bed6e0a18bd5b76fb581ede10121f8c14a6f7)
-    // manually set the required one:
-    // ndkVersion flutter.ndkVersion
-    ndkVersion = "25.1.8937393"
+    ndkVersion flutter.ndkVersion
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8

objectbox/example/flutter/objectbox_demo_relations/android/app/build.gradle

@@ -25,13 +25,7 @@ if (flutterVersionName == null) {
 android {
     namespace "com.example.objectbox_demo_relations"
     compileSdkVersion flutter.compileSdkVersion
-    // ObjectBox: Flutter defaults to NDK 23.1.7779620, but
-    // - objectbox_flutter_libs requires Android NDK 25.1.8937393
-    // - path_provider_android requires Android NDK 25.1.8937393
-    // Until Flutter uses a newer version (https://github.com/flutter/flutter/commit/919bed6e0a18bd5b76fb581ede10121f8c14a6f7)
-    // manually set the required one:
-    // ndkVersion flutter.ndkVersion
-    ndkVersion = "25.1.8937393"
+    ndkVersion flutter.ndkVersion
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8

objectbox/example/flutter/objectbox_demo_sync/android/app/build.gradle

@@ -25,13 +25,7 @@ if (flutterVersionName == null) {
 android {
     namespace "com.example.objectbox_demo_sync"
     compileSdkVersion flutter.compileSdkVersion
-    // ObjectBox: Flutter defaults to NDK 23.1.7779620, but
-    // - objectbox_flutter_libs requires Android NDK 25.1.8937393
-    // - path_provider_android requires Android NDK 25.1.8937393
-    // Until Flutter uses a newer version (https://github.com/flutter/flutter/commit/919bed6e0a18bd5b76fb581ede10121f8c14a6f7)
-    // manually set the required one:
-    // ndkVersion flutter.ndkVersion
-    ndkVersion = "25.1.8937393"
+    ndkVersion flutter.ndkVersion
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8