Stick this in your fullscreen Activities

Who knows if this is "right". I don't care. Just stick this in your fullscreen Activites to avoid pain and sorrow every time you create a new one.

ViewCompat.setOnApplyWindowInsetsListener(root) { view, insets ->
  val systemBarsInsets = insets.getInsets(WindowInsetsCompat.Type.navigationBars())
  view.setPadding(0, systemBarsInsets.top, 0, systemBarsInsets.bottom)
  insets
}

// 31 or higher
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
  window.insetsController?.let {
    it.systemBarsBehavior = android.view.WindowInsetsController.BEHAVIOR_DEFAULT
  }
} else {
  @Suppress("DEPRECATION")
  window.clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN)
}