Android: Add Void conversion support to QAndroidTypeConverter

Now the caller of toJavaObject() is be able to get
an object of Void type when the input parameter is QVariant<void*>.

Fixes: QTBUG-128586
Pick-to: 6.8
Change-Id: I6eea670788461e4eb0d8f38a4a872c2c4759bdd8
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
Reviewed-by: Petri Virkkunen <petri.virkkunen@qt.io>

src/corelib/platform/android/qandroidtypeconverter_p.h

@@ -79,6 +79,8 @@ namespace QAndroidTypeConverter
             return env->NewLocalRef(QJniObject::construct<QtJniTypes::Boolean>(
                                             get<bool>(var))
                                             .object());
+        case QMetaType::Type::VoidStar:
+            return env->NewLocalRef(QJniObject::construct<QtJniTypes::Void>().object());
         case QMetaType::Type::QString:
             return env->NewLocalRef(
                     QJniObject::fromString(get<QString>(var)).object());