Merge pull request #66694 from spiffxp/dd-status-none

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>.

dd status=none does not exist on macOS

**What this PR does / why we need it**:

When running cluster/kubectl.sh on macOS 10.13.6, the use of the
`status=none` operand leads to `dd: unknown operand status` being
printed out as an error message. Redirecting to /dev/null does
the same thing, supressing transfer status.

```release-note
NONE
```

cluster/gce/config-default.sh

@@ -216,7 +216,7 @@ resources:
     - aesgcm:
         keys:
         - name: key1
-          secret: $(dd if=/dev/random bs=32 count=1 status=none | base64 | tr -d '\r\n')
+          secret: $(dd if=/dev/random bs=32 count=1 2>/dev/null | base64 | tr -d '\r\n')
 EOM
 )
 fi