Automatic merge from submit-queue (batch tested with PRs 68265, 68273). If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.

gke: fix failing e2e tests

```
/home/kubernetes/bin/configure-helper.sh: line 2032: ENABLE_NODE_TERMINATION_HANDLER: unbound variable
```

```release-note
NONE
```