Increase cluster sync timeout for M->N major upgrades

Increase cluster sync timeout for M->N major upgrades

Since the Liberty release, the number of services managed by pacemaker
on HA Overcloud has increased. This has an impact on
major_upgrade_controller_pacemaker_1.sh, where cluster sync timeout
value tuned for older releases is now becoming too low.

Raise the cluster sync timeout value to a sensible limit to
give pacemaker enough time to stop the cluster during major upgrade.

Change-Id: I821d354ba30ce39134982ba12a82c429faa3ce62
Closes-Bug: #1597506