Animation not triggered on increasing/decreasing ListView's currentIndex

This was seen with qt/qt-qml HEAD at 9ae50ce40c1bc571c867bc698f2c53839c2c6932
and tesla HEAD at d42ab8ba16614972d1e24157a86086c0b17e19f6

In the tesla launcher, long press an icon to enter edit mode. Then drag an icon to the
right-hand side of the screen and wait for the time-out. Note how the list of icons
change to the next page, but instantaneously rather than with the expected sliding
animation. N.B. this is the only instance where this problem has been seen (i.e. it
usually works).

See AppItem.qml lines 98-107