Use test specific word engine in preedit string test.
Use test specific word engine in preedit string test.

RevBy: Michael Hasselmann

This work was done by Openismus GmbH for Canonical Ltd

develersrl/maliit-demo-qml,develersrl/maliit-demo-qml,maliit/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,RHawkeyed/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,maliit/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,develersrl/maliit-demo-qml,develersrl/maliit-demo-qml,maliit/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,maliit/plugins