Button sticking on iOS and Android

[Juason]

Occasionally GUI buttons will depress without firing the appropriate handler. I noticed this initially with the default Toy UI, and later with my own game. The button will appear depressed but not un-depress and not fire. This can sometimes result in multiple buttons appearing to be depressed simultaneously and continuously.

I've not had time to debug it will be post more info as time allows. Thanks!

[chaigler]

I remember reports of GuiButtonCtrls appearing to 'stick' in the depressed state going back to TGE, but I thought those issues had long since been resolved. As a starting point, it'd be good to pin down if this is related to the other Android/iOS input issues or something that affects all of the platforms.