Make the build work with Qt 6.8.1 (and newer)

As for now, this is just for Qt debuging as multiple stuff is broken in Qt 6.8.1
- The new style has serious render issues
- Reading files in a directory is by multiple order of magnitude slower
- The zoom gestures do not work reliably

Qt versions prior to 6.8.1 are completely unusable due to the broken main menu.

pkg/android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.2.1'
+        classpath 'com.android.tools.build:gradle:8.6.0'
     }
 }
 
@@ -14,10 +14,12 @@ repositories {
     mavenCentral()
 }
 
-apply plugin: 'com.android.application'
+apply plugin: qtGradlePluginType
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
+    //noinspection GradleDependency
+    implementation 'androidx.core:core:1.13.1'
 }
 
 android {
@@ -28,14 +30,15 @@ android {
      * - qtAndroidDir - holds the path to qt android files
      *                   needed to build any Qt application
      *                   on Android.
+     * - qtGradlePluginType - whether to build an app or a library
      *
      * are defined in gradle.properties file. This file is
      * updated by QtCreator and androiddeployqt tools.
      * Changing them manually might break the compilation!
      *******************************************************/
 
-    //compileSdkVersion androidCompileSdkVersion
-    compileSdkVersion "android-33"
+    namespace androidPackageName
+    compileSdkVersion androidCompileSdkVersion
     buildToolsVersion androidBuildToolsVersion
     ndkVersion androidNdkVersion