OCPBUGS-63386: Increase agent-installer pre-network-manager timeout

We have a report that a baremetal installation with VLAN interfaces
can require longer than the current setting for the timeout of
the pre-network-manager-config service. Increasing it to 300
seconds.

Author: bfournie

data/data/agent/systemd/units/pre-network-manager-config.service

@@ -6,7 +6,7 @@ DefaultDependencies=no
 [Service]
 User=root
 ExecStart=/usr/local/bin/pre-network-manager-config.sh
-TimeoutSec=60
+TimeoutSec=300
 Type=oneshot
 PrivateTmp=true
 RemainAfterExit=no