Support running in custom Linux group

[LwServices]

When is start my app and access to GPIO
App throws System.UnauthorizedAccessException: 'Setting a mode to a pin requires root permissions.'

change group to gpio solved my issue

pi@busterhat:~/vsdbg/RemoteIo $ ls -al | grep RemoteIo
-rwxrwx---  1 pi pi   77512 Dec 21 13:10 RemoteIo

pi@busterhat:~/vsdbg/RemoteIo $ chgrp gpio RemoteIo
pi@busterhat:~/vsdbg/RemoteIo $ ls -al | grep RemoteIo
-rwxrwx---  1 pi gpio   77512 Dec 21 13:10 RemoteIo

[jefflill]

Merged into: main