redhat-upgrade-tool fails to reconfigure the network interfaces, preventing the upgrade to happen

Issue

• When executing redhat-upgrade-tool through a SSH connection, the command hangs after shutting down the network interfaces and the system is not pingable anymore

  # redhat-upgrade-tool --device /mnt/rhel76
  [...]
  Shutting down interface eth0:  Device state: 3 (disconnected)
  [  OK  ]
  Shutting down interface eth1:  Device state: 3 (disconnected)
  <HANG HERE>
  

• When executing redhat-upgrade-tool from the system console, the command fails as shown below

  # redhat-upgrade-tool --device /mnt/rhel76
  [...]
  Shutting down interface eth0:  Device state: 3 (disconnected)
  [  OK  ]
  Shutting down interface eth1:  Device state: 3 (disconnected)
  [  OK  ]
  Shutting down loopback interface:  [  OK  ]
  RTNETLINK answers: Device or resource busy
  RTNETLINK answers: Device or resource busy
  Bringing up loopback interface:  lo: Disabled Privacy Extensions
  [  OK  ]
  Bringing up interface net0:  Active connection state: activating
  Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/2
  Error: Connection activation failed: The connection is not for this device.
  [FAILED]
  Bringing up interface net1:  Error: Connection activation failed: The connection is not for this device.
  [FAILED]
  Following preupgrade script(s) failed:
  
  /root/preupgrade/preupgrade-scripts/rename_network.sh exited with status 1
  exiting