well, I am sorry to say but the code doesn't help at all.
First of all you did not define StickerManager (but I assumed it's a manager - not a screen as one would guess by the variable name)
This was my initial approach (only I used a more useful PopupScreen with applyTheme() overloaded) but it has a major flaw:
Once the screen is displayed you cannot have access to the VoiceApp's Menu.
Basically we created a new screen with it's own menu handling system.
So, you see, this code actually does much more than I need, and much less than I require
.
But, anyway thank you for the input.