Expose controller_public_protocol

Commit I49c751a8b68a49e6f15c4e213c0ddbbec7076229 created a data
mapping for the protocol used to access API services on the
control node.  However it didn't set that variable in a hiera_data/*
file, which can lead to errors during puppet runs due to required
variables being missing.

Change-Id: Ie197a82d07a43e176bc27b7c0cbaea6d51e10a12
Closes-Bug: #1285774