Ensure add_on_others in autoyast profile are added (bsc#1223301)

[mvidner]

Problem

When upgrading from SLE12 (SP5) to SLE15-SP5 via AutoYaST,
when <add_on_others> repositories are specified in the profile ("others" meaning, plain, non-product repos),
these repos are not present when the upgrade finishes.

• https://bugzilla.suse.com/show_bug.cgi?id=1223301
• https://trello.com/c/sppEpu4L

Solution

Add a Pkg.SourceSaveAll call to reinit_repos that reinits the repos in the middle of the upgrade.

Testing

Tested manually. After the upgrade, the add_on_others repo is present and SLE12 repos are not present.

• with AutoYaST and registration
• manually, with registration
• manually, without registration (full medium)

Helpful tools:

• When you start an upgrade but abort it in the proposal screen before hitting the big green button, SCC considers it upgraded/migrated already. Use suseconnect --rollback to revert its records
• yupdate overlay create (https://github.com/yast/yast-installation/blob/master/doc/yupdate.md)

Screenshots

N/A

[lslezak]

The fix looks OK to me. Please add changes and update the PR description.

[lslezak]

LGTM

However, please test it also in manual (non-AutoYaST) migration. Test both cases - offline upgrade from DVD medium (without registration) and online upgrade using SCC (registered system).

This code was originally added to fix some problem with removing the old repositories during migration, we should be sure there is no regression regarding this.

[lslezak]

LGTM, thanks!

[yast-bot]

✔️ Internal Jenkins job #753 successfully finished
✔️ Created IBS submit request #332704