Update nr_hugepages on ocp13 and ocp23

[jpmckinney]

I reduced shared_buffers to 8GB, because apparently there might not be much advantage to go over that: https://github.com/jberkus/annotated.conf/blob/master/postgresql.10.simple.conf#L84-L87

I originally set nr_hugepages following this process:
https://www.postgresql.org/docs/14/kernel-resources.html#LINUX-HUGE-PAGES

As documented here: https://ocdsdeploy.readthedocs.io/en/latest/develop/update/postgres.html

However, this requires us to "start PostgreSQL without huge pages enabled"

I think there is no great consequence to having a larger nr_hugepages than necessary, but logging here in case easy to do.

[jpmckinney]

@RobHooper Do we want to update nr_hugepages on ocp27?