title: The native method is not called after switching to the new qt and Gradle
body: <p>Call of native C++ functions from Java stopped working.</p>
  
  <p>With Qt5.10/gradle:2.3.3/ndk-r16b/jdk-1.7.0-55 worked fine:</p>
  
  <p><strong>MainActivity.java</strong></p>
  
  <pre><code>package com.mypackage;
  ...
  public class MainActivity extends QtActivity
  {
      @Override
      public void onCreate(Bundle savedInstanceState) {
          s_instance = this;
          super.onCreate(savedInstanceState);
          ...
          registerNatives();
          ...
      }
  
      private native void registerNatives();
  }
  </code></pre>
  
  <p><strong>somecppfile.cpp</strong></p>
  
  <pre><code>#include &lt;QAndroidJniObject&gt;
  #include &lt;QAndroidJniEnvironment&gt;
  #include &lt;jni.h&gt;
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  JNIEXPORT void JNICALL
  Java_com_mypackage_MainActivity_registerNatives(JNIEnv *env, jobject)
  {
     ... // 
  }
  #ifdef __cplusplus
  }
  #endif
  </code></pre>
  
  <p>After changing versions when running on Android error occurs.
  Qt5.12/gradle:3.2.0/ndk-18.1.5063045/jdk-1.8.0-192</p>
  
  <pre><code>E zygote  : No implementation found for void com.mypackage.MainActivity.registerNatives() (tried Java_com_mypackage_MainActivity_registerNatives and Java_com_mypackage_MainActivity_registerNatives__)
  D AndroidRuntime: Shutting down VM
  E AndroidRuntime: FATAL EXCEPTION: main
  E AndroidRuntime: Process: com.mypackage, PID: 26735
  E AndroidRuntime: java.lang.UnsatisfiedLinkError: No implementation found for void com.mypackage.MainActivity.registerNatives() (tried Java_com_mypackage_MainActivity_registerNatives and Java_com_mypackage_MainActivity_registerNatives__)
  E AndroidRuntime:   at com.mypackage.MainActivity.registerNatives(Native Method)
  E AndroidRuntime:   at com.mypackage.MainActivity.onCreate(MainActivity.java:95)
  E AndroidRuntime:   at android.app.Activity.performCreate(Activity.java:7372)
  E AndroidRuntime:   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1218)
  E AndroidRuntime:   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3147)
  E AndroidRuntime:   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3302)
  E AndroidRuntime:   at android.app.ActivityThread.-wrap12(Unknown Source:0)
  E AndroidRuntime:   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1891)
  E AndroidRuntime:   at android.os.Handler.dispatchMessage(Handler.java:108)
  E AndroidRuntime:   at android.os.Looper.loop(Looper.java:166)
  E AndroidRuntime:   at android.app.ActivityThread.main(ActivityThread.java:7425)
  E AndroidRuntime:   at java.lang.reflect.Method.invoke(Native Method)
  E AndroidRuntime:   at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
  E AndroidRuntime:   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)
  I Process : Sending signal. PID: 26735 SIG: 9
  </code></pre>