Return main status through JNI entry points

This is currently unused, but without passing back the status the Java
classes have no way of knowing whether the native code succeeded or not.

Author: zworkb

pythonforandroid/bootstraps/common/build/jni/application/src/start.c

@@ -348,7 +348,7 @@ int main(int argc, char *argv[]) {
   return ret;
 }
 
-JNIEXPORT void JNICALL Java_org_kivy_android_PythonService_nativeStart(
+JNIEXPORT int JNICALL Java_org_kivy_android_PythonService_nativeStart(
     JNIEnv *env,
     jobject thiz,
     jstring j_android_private,
@@ -388,7 +388,7 @@ JNIEXPORT void JNICALL Java_org_kivy_android_PythonService_nativeStart(
   /* ANDROID_ARGUMENT points to service subdir,
    * so main() will run main.py from this dir
    */
-  main(1, argv);
+  return main(1, argv);
 }
 
 #if defined(BOOTSTRAP_NAME_WEBVIEW) || defined(BOOTSTRAP_NAME_SERVICEONLY)
@@ -411,7 +411,7 @@ void Java_org_kivy_android_PythonActivity_nativeSetenv(
 }
 
 
-void Java_org_kivy_android_PythonActivity_nativeInit(JNIEnv* env, jclass cls, jobject obj)
+int Java_org_kivy_android_PythonActivity_nativeInit(JNIEnv* env, jclass cls, jobject obj)
 {
   /* This nativeInit follows SDL2 */
 
@@ -427,7 +427,7 @@ void Java_org_kivy_android_PythonActivity_nativeInit(JNIEnv* env, jclass cls, jo
   argv[1] = NULL;
   /* status = SDL_main(1, argv); */
 
-  main(1, argv);
+  return main(1, argv);
 
   /* Do not issue an exit or the whole application will terminate instead of just the SDL thread */
   /* exit(status); */

pythonforandroid/bootstraps/common/build/src/main/java/org/kivy/android/PythonService.java

@@ -201,7 +201,7 @@ public void run(){
     }
 
     // Native part
-    public static native void nativeStart(
+    public static native int nativeStart(
             String androidPrivate, String androidArgument,
             String serviceEntrypoint, String pythonName,
             String pythonHome, String pythonPath,