Minor tweak to allow access to lvm_vg_reuse proposal via an AY profile

[mchf]

Problem

See yast/yast-storage-ng#1365

should be merged after the above one.

This change makes following snipped working (sets lvm_vg_reuse in created proposal(s) accordingly):

<general>
    <storage>
      <proposal>
        <lvm_vg_reuse config:type="boolean">false</lvm_vg_reuse>
      </proposal>
  </storage>
</general>

Testing

• Tested manually

[coveralls]

coverage: 68.713%. remained the same
when pulling 19903a3 on mchf:SLE-15-SP6
into a0e92a7 on yast:SLE-15-SP6.

[ancorgs]

This would need some update to the corresponding AY documentation, specifying what are the valid values and so on.

[ancorgs]

Generally, LGTM. Just some notes for the record:

• It would have been nice to extend the unit tests at autoinst_storage_test.rb They already cover settings like lvm or encryption_password
• I double-checked and I see the different attributes of general/proposals/storage are not mentioned in the schema, so this PR is fine as it is in that regard
• It would be nice, nevertheless, to mention this new setting in the corresponding AutoYaST documentation

[yast-bot]

✔️ Internal Jenkins job #4 successfully finished
✔️ Created IBS submit request #321659