Flickable doesn't work with touch input and touch-only content item

If you put a touch-only component inside a Flickable and then try to flick it, with touch, it won't work (Flickable won't move its contentItem at all).

It works if you interact with the Flickable using a mouse device or if you simply call setAcceptedMouseButtons(Qt::LeftButton) in your touch-only component.

This is a regression in 5.10 as it used to work in 5.9.

See the attached test application for details.

I suppose this bug would go under the QTBUG-30840 umbrella.