When the description label is not present, the title label increases
its implicit height to attempt to match it so that all list delegates
have the same height. However it was using a faulty calculation by
simply doubling its own implicitHeight. This would have worked if both
labels had the same height, but they don't: the description label uses
the small font, so it's shorter.

We can fix this by using the description label's actual height instead
of approximating it incorrectly.

BUG: 479287
FIXED-IN: 6.0