Used fixed name for dummy ipv6 interface to avoid length issue (#1447)

As tracked in #1124,
interface creation can fail if the name exceeds 15 characters. Ensure that
for long cluster name the dummy interface that is created will not exceed
this lenght by using a fixed name.

02_configure_host.sh

@@ -242,7 +242,7 @@ fi
 # The IPv6 bridge interface will remain in DOWN state with NO-CARRIER unless an interface is added,
 # so add a dummy interface to ensure the bridge comes up
 if [[ -n "${EXTERNAL_SUBNET_V6}" ]] && [ ! "$INT_IF" ]; then
-    sudo ip link add name ${BAREMETAL_NETWORK_NAME}-dummy up master ${BAREMETAL_NETWORK_NAME} type dummy
+    sudo ip link add name bm-ipv6-dummy up master ${BAREMETAL_NETWORK_NAME} type dummy || true
 fi
 
 IPTABLES=iptables

host_cleanup.sh

@@ -53,8 +53,8 @@ fi
 if [ "$MANAGE_BR_BRIDGE" == "y" ]; then
     sudo ifdown ${BAREMETAL_NETWORK_NAME} || true
     sudo ip link delete ${BAREMETAL_NETWORK_NAME} || true
-    if [[ -d /sys/class/net/${BAREMETAL_NETWORK_NAME}-dummy ]]; then
-       sudo ip link delete ${BAREMETAL_NETWORK_NAME}-dummy || true
+    if [[ -d /sys/class/net/bm-ipv6-dummy ]]; then
+       sudo ip link delete bm-ipv6-dummy || true
     fi
     sudo rm -f /etc/sysconfig/network-scripts/ifcfg-${BAREMETAL_NETWORK_NAME}
 fi