Initialize flutter-homescreen repo

A repository to host the demo Flutter homescreen is required on AGL git / Gerrit.  Please create a apps/flutter-homescreen repo that is initialized as a clone of:

https://github.com/felipeerias/flutter_homescreen.git

to serve as the starting point of development.  As I aim to do initial modifications on it to run in the agl-ivi-demo-platform-flutter image It seems reasonable to have myself as a/the listed maintainer for now, with perhaps @José Dapena Paz and/or @Lorenzo also on the list if they wish.