Fix Ctrl + Enter Autoplay shortcut animation

[Xiragi]

Addresses: #35973

#36068 (comment)

[LiquidPL]

The reason why the buttons don't animate properly is because upon transition to a new screen they are moved to hiddenButtonsContainer which is just a plain Container, and not a fill flow container, because of which the buttons are no longer doing any relayouts.

Also, button.DisappearToBottom() immediately calls FinishTransforms() which interrupts the resize transform, and causes drawables to additionally jump around.

I guess I'm writing this more because I'm starting to wonder if there is a need to call FinishTransforms() on every appear/disappear, or could we only call that method in some places where it is necessary (ideally not when changing screens), which would possibly solve this issue.

[Xiragi]

seems worth investigating. didn't feel right to me to be updating the positions manually

[peppy]

This cannot exist without inline commenting precisely explaining what it's doing.