Add owner_id to the external-dns documentation example

[meyskens]

Add owner_id to the external-dns documentation example

Discovered a missing example field when doing release testing. As this is required makes the example non functional.

How to use

Read the documentation

Testing done

used in a release test

[meyskens]

cc @johananl

[meyskens]

Let's see if I can get the CI to be happy :)

[surajssd]

I use the cluster name for this field.

owner_id = var.cluster_name

Which is generally unique. But I don't have a strong opinion on what the value should be set to ideally.

[ipochi]

I agree with @surajssd

Rather than hard coding an example value lokomotive we should use a variable. The value of cluster_name seems to be a good choice, however what if two clusters are created with the same cluster name ?