add root_user variable

[james-bruten-mo]

While reviewing the linter ticket I realised that some commands in the kgo scripts were hardcoded to frum instead of using umadmin as they are on azspice. This ticket fixes that.

[ericaneininger]

This looks fine to me.
There are a couple of comments in the file which still specify "frum" where perhaps they shouldn't now, but functionally this is fine.
Examples at L9, L126, L145

[t00sa]

I agree with Erica that this wants a bit more tidying up. I'd suggest the following:

• Move L148 to after L32 to define root_user=frum
• Move L151 to after L24 to define root_user="umadmin"

Then do a wholesale search-and-replace to swap frum and umadmin for ${root_user}.

It may also make sense to use this as an opportunity to set another variable in the same initial section between L22 and L33 to define an install directory for each platform, e.g. root_home=/home/users/${root_user}, and replace any hardwired referenced to the home directory. This future-proofs the script in the event that we decide we need to remove the explicit username references.

[james-bruten-mo]

Cheers Sam, done those. There's definitely tidying that could be done for the root_home still, but they're not simple copy and pastes so I'll leave for slower time. Any actual refactor would be better left until we've removed old platforms I think.

[t00sa]

Thank you! Changes look good to me.