Puppet: define swift_store_auth_address in hiera

Puppet: define swift_store_auth_address in hiera

This patch updates the glance::backend::swift implementation to
use only hiera variables instead of a mix of hiera, and inline
class variables.

Nothing was functionally wrong with the previous approach but now
that we can compose more freely using the SoftwareDeployment defining
all the variables in Hiera makes sense and is cleaner.

Change-Id: I6d319841488d2ed94e088a5ac21e41dcd964ed1a
Co-Authored-By: Dan Prince <dprince@redhat.com>