Follow the screen shots.
first make sure 9.0 (api 28) run in your Emulater or testing device.
- Open System settings.
- Open Developer option (*if u not found developer option please tap 7 times on build number. after that you get developer option.)
- Scroll Down Until You Found -> Simulate a Display With a Cutout(click on it)
- there is a multiple option to select screen Cutout style.
- if you select Tall Display Cutout , your display is like that.
or if you select Double Display Cutout your display like.