Checklist: implementing onActivityCreated()

- drone variable assignement & sysLink initialization is now moved to
onActitiviyCreated as suggested by https://github.com/ne0fhyk

- tested and working beautifully - thanks to https://github.com/ne0fhyk
Merge pull request #408 from azrin1972/Checklist-OnActivityCreated

Checklist: implementing onActivityCreated()