Cannot start a VM with error "Network not found: no network with matching name" in RHV

Issue

• All VMs in a cluster fails to start with the error below.

2018-05-04 22:34:48,963+0530 ERROR (vm/ae1fa9b0) [virt.vm] (vmId='ae1fa9b0-c42d-47ba-a966-6ff7c7afa0e7') The vm start process failed (vm:632)
Traceback (most recent call last):
  File "/usr/share/vdsm/virt/vm.py", line 563, in _startUnderlyingVm
    self._run()
  File "/usr/share/vdsm/virt/vm.py", line 2021, in _run
    self._connection.createXML(domxml, flags),
  File "/usr/lib/python2.7/site-packages/vdsm/libvirtconnection.py", line 123, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/vdsm/utils.py", line 941, in wrapper
    return func(inst, *args, **kwargs)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 3777, in createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self)
libvirtError: Network not found: no network with matching name 'vdsm-TEST-RHV-TEST-MGMTNTWRK'

• The display network is having character length greater than 15 characters.