A well-crafted concept video of the upcoming Samsung Galaxy A90 smartphone has been posted on YouTube, and it shows what is apparently the South Korean manufacturer's solution for the pesky selfie camera. The camera setup is located on a sliding mechanism, which moves up from the rear of the device and the camera module can be rotated to face either the front or rear.
https://www.notebookcheck.net/Almost-completely-correct-sliding-and-rotating-selfie-camera-shown-off-in-fantastic-Samsung-Galaxy-A90-concept-video.415832.0.html