code clarity changes
support older than android-11
only instantiate NsdHelper on Android versions that support NSD
move generateQrCode() to static method in Utils

This makes it easy to use in multiple Activities.
REBASE only instantiate NsdHelper on Android versions that support NSD
create wizard for bootstrapping with QR Code and wifi
local repo port, IP and IP String as app global

This stores globally variables for the IP address, port number, and
string version of the IP address. They can then be easily used elsewhere,
in other Activities, etc.
REBASE create wizard for bootstrapping with QR Code and wifi