Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Allow Ceph server some time to start

Ceph server needs to create our "foo" volume on startup. It keeps the image small, however it makes the server container start slow.

Add sleep before the server is usable. Without this PR, all pods that use Ceph fail to start for couple of seconds with cryptic "image foo not found" error and it clutters logs and pod logs and makes it harder to spot real errors.

```release-note
NONE
```

/sig storage
/sig testing
/assign @jeffvance @copejon