Use variables instead of raw strings.
Use variables instead of raw strings.

RevBy: TrustMe
Reasons noted in previous commit.

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