OSKController enabled property is reported incorrectly

I'm using the enabled property of the OSKController to check when we're ready to proceed with the autopilot test (as it restarts the maliit-server).

The problem is that it never changes from True even when I `initctl stop maliit-server`

To reproduce (with help with this script [1]) / what I see:

# Start unity8 with testability so we can introspect it
$ stop unity8 && start unity8 QT_LOAD_TESTABILITY=1
$ status unity8
>>> unity8 start/running, process 2273

$ status maliit-server
>>> maliit-server start/running, process 2443

$ check_status.py 2273 # The script from [1]
>>> (Checking OSKController.enabled)
>>> Status: True

$ stop maliit-server && status maliit-server
>>> maliit-server stop/waiting

$ check_status.py 2273 # The script from [1]
>>> (Checking OSKController.enabled)
>>> Status: True

The output of the second run should be False.

Perhaps the OnSurfaceCreated/onSurfaceDestroyed from OSKController.qml isn't being called as expected?

[1] http://pastebin.ubuntu.com/6373981/