We are using the calls page with a picture in picture(pip) feature.
Problem :
In case user dismiss the pip popup window (by drag down to dismiss) we not able to detect that. 
How to detect picture in picture window drag down to dismiss?
Update:
Set picture in picture
// RemoteRenderLayout -> call preview layout. You can set anyone view
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
Rational aspectRatio = new Rational(
remoteRenderLayout.getWidth(), remoteRenderLayout.getHeight());
PictureInPictureParams params = new PictureInPictureParams.Builder()
.setAspectRatio(aspectRatio)
.build();
enterPictureInPictureMode(params);
}
else{
enterPictureInPictureMode();
}