Update brg topo activate DG

brg-topology-operation-activate should
setup vxlan port/tunnel between vBRG
and vgMUX. This patch adds
the vcpe-vpp-bridge-domain.json template
and edits brg topo activate DG and
the generic-resource-api-dg.properties
to enable setup of the vxlan tunnel.

Issue-Id: SDNC-164
Change-Id: Ic5e473f16e2fb2e90149619accc857a64c3dbbd2
Signed-off-by: Marcus G K Williams <marcus.williams@intel.com>
Former-commit-id: 8235f3c0e35d379937e6e12130435aa76a5ac0bf