Commit 53ec6e6 missed to remove this deferred call (probably due to a
rebase).
I noticied it while working with the code. I'm not sure why the original
commits removes them, but it seems the right thing to do.
This patch adds a secret e2e test. While configmap e2e tests are far
more complete, this patch makes secret e2e tests one step closer.
Also, now is more easy to add more tests without code duplication (as I
did in earlier patches :-/), because of the functions created, and is
more easy to make it similar to confimap e2e in the future, that is
really complete.
This implements the proposal in:
docs/proposals/secret-configmap-downwarapi-file-mode.md
Fixes: #28317.
The mounttest image is updated so it returns the permissions of the linked file
and not the symlink itself.
