Issue

It is necessary to permanently disable a default systemd configuration for a specific unit file.
For example in the rpcbind service comes with IPv6 configuration enabled by default:

# cat /usr/lib/systemd/system/rpcbind.service 
[Unit]
Description=RPC bind service
DefaultDependencies=no

# Make sure we use the IP addresses listed for
# rpcbind.socket, no matter how this unit is started.
Wants=rpcbind.socket   
After=rpcbind.socket
After=systemd-tmpfiles-setup.service

[Service]
Type=forking
EnvironmentFile=/etc/sysconfig/rpcbind
ExecStart=/sbin/rpcbind -w $RPCBIND_ARGS


# cat usr/lib/systemd/system/rpcbind.socket 
[Unit]
Description=RPCbind Server Activation Socket

[Socket]
ListenStream=/var/run/rpcbind.sock
ListenStream=[::]:111             <-------------
ListenStream=0.0.0.0:111
BindIPv6Only=ipv6-only     <------------

[Install]
WantedBy=sockets.target

It is possible to manually remove those lines, but they will be back upon update. How do we remove them permanently?