No way to hide exit preview button

[ahmaadaziz]

I have an editor instance in which I simply want to show a preview of a previously configured template, like so in the onReady callback function:
editor.showPreview({});

This works, but the exit preview button remains visible, which the user can click to exit out of preview mode. This defeats on of the main purposes of showPreview as the user can simply exit out of it anytime they want.