Downward API volume should update labels on modification

[0xmichalis]

https://openshift-gce-devel.appspot.com/build/origin-ci-test/pr-logs/pull/18074/test_pull_request_origin_extended_conformance_install/5696/

Happens frequently

@openshift/sig-storage
/kind test-flake

[sosiouxme]

Is this different from #17882 ?

[dcbw]

Is this different from #17882 ?

Looks like the same one...

[mfojtik]

Attempted fix: #18444.

The other failure related to downward api seemed to be fixed in #18387, maybe this one will be same.