Replace all the bridge_name variables in templates
Replace all the bridge_name variables in templates

The bridge_name might be used for multiple times, for example,
in different vlan configurations. All of them should be replaced with
the actual ${bridge_name} variable.

Change-Id: I93ee204a526422f113a88b99531583e3cf769382
Closes-Bug: #1866393

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates