Add workaround for QT Lighthouse to example.
Add workaround for QT Lighthouse to example.

Use correct input context also in QT Lighthouse case, where the
environment variable currently does not work.

RevBy: Jon Nordby

binlaten/framework,Elleo/framework,jpetersen/framework,sil2100/maliit-framework,jpetersen/framework,Elleo/framework,RHawkeyed/framework,RHawkeyed/framework,sil2100/maliit-framework,sil2100/maliit-framework,sil2100/maliit-framework