Qt dependencies from extraLibs are not included in APK

While creating an Android app containing activity and service in separate libs the Qt dependencies of the library that contains service implementation are not scanned by androiddeployqt and thus - not included in APK.
Just use example from KDAB page: https://www.kdab.com/qt-android-create-android-service-using-qt/
Section: "Separate .so files for app & service(s)"
After adding:

QT += sql

to service pro file libQt5Sql.so won't get into APK.
Same thing when we just add our own library to extraLibs - it is built with the same Qt but its dependencies won't be scanned and thus won't get into APK.