Update 15km ocean file defaults

[gdicker1]

Quoting @dazlich:

The default ocean/seaice files for 15km have been updated to use a new one that does not initially generate unstable transients.

These modifications are in the mpas-ocean, mpas-seaice, and ccs_config components.

[gdicker1]

Sub-PRs:

• Update 15km file defaults ccs_config_cesm#33
• Update 15km file defaults mpas-seaice#20
• Update 15km file defaults mpas-ocean#18

[gdicker1]

@dazlich, all the Sub-PRs for this are approved. I could easily find the new files needed. Thanks for the work on these!

When you have time, it might be good to expand the number of graph partition files for mpas-o.graph.info.QU015.241221 beyond the 100 node config.

[dazlich]

I was just about to mention the graph partitions - I will check which ones currently exist for the atmosphere and start there.