Convert PublicVirtualIP to new port creation method

Convert PublicVirtualIP to new port creation method

This change brings PublicVirtualIP in line with the rest of the
VIPs in how it is created. This allows the network where
PublicVirtualIP is instantiated to be on cltplane when network
isolation is not used, and on the external network when network
isolation is used. This change removes the PublicVirtualNetwork
parameter, since it is no longer used. In order to continue to
support the PublicVirtualFixedIPs parameter, which is used to
provide a specific IP for the PublicVirtualIP, the FixedIP
parameter was added to cltplane_vip.yaml, vip.yaml, and
noop.yaml. The value of PublicVirtualIP is passed to FixedIP
in the VIP templates. This change also moves the default
network for keystone public api to the external net (which will
fallback to ctlplane if network isolation isn't used).

Change-Id: I3f5d35cbe55d3a148e95cf49dfbaad4874df960b