Issue - on a touch screen only device, switching into fullscreen mode displaying the message "Press ESC to exit full-screen mode." does not make any sense.

There is two parts to a solution for the issue -
   1) recognizing a situation where there is no keyboard present
   2) not displaying the mesage in
        com/sun/javafx/tk/quantum/OverlayWarning.java: OverlayWarning(final ViewScene vs)
    or more probably, in WindowStage.applyFullScreen(), and not create the overlay at all.

The easiest for #2 would be a PlatformUtils query.

for #1, we may need to just use a system property, allowing embedded apps to disable the behavior.