Rework #2828 to avoid changing answers for E3SM

[billsacks]

#2828 updated datm in a way that likely affected e3sm as well as cesm, but these changes aren't actually wanted in e3sm (yet). @ekluzek will rework this to distinguish between cesm and e3sm.

Initial questions before @ekluzek tackles this:

(1) @jgfouca can you let us know once you have confirmed that that PR was indeed responsible for some of the unexpected diffs you were seeing?

(2) @rljacob and/or @jgfouca - do you want Erik to fix this on maint-5.6 or just the master branch?

[jedwards4b]

I'm pretty sure that they are only working with master and not maint-5.6

[rljacob]

Just master.

[jgfouca]

@billsacks , confirmed. The change to namelist_definition_datm.xml causes the DIFF.

[billsacks]

Thanks, @jgfouca . So, @ekluzek can you please make this change on master when you get a chance in your schedule?

[ekluzek]

OK

[jgfouca]

@ekluzek , I had to fix this on E3SM in order to get things to work without DIFFing. You can see the fix here: E3SM-Project/E3SM@11099cf

If you are OK with this fix, you don't need to do anything. It will come into ESMCI/CIME with the next E3SM split.

[ekluzek]

OK, I took a look and it looks correct to me. I made one comment that you can take or reject.

[rljacob]

telecon: fixed.