Hey! I've found the solution myself again.)) I answered it at StackOverflow:
https://stackoverflow.com/questions/25340593/issue-with-fullscreen-mode-in-android-with-qt-5-3-1/59469941#59469941
Here is my result:
photo_2019-12-24_19-14-51.jpg
The status and navigation bars are hidden:
photo_2019-12-24_19-14-53.jpg

@mcosta Thank you it all finally working fine :)