Automatic merge from submit-queue (batch tested with PRs 62436, 62499, 62664, 62685, 62660). 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>.
kazel: skip third_party/etcd.*
**What this PR does / why we need it**: fixes the issue encountered in https://github.com/kubernetes/kubernetes/pull/62151#discussion_r179322174.
Basically, we git ignore anything under `third_party/etcd.*`, but if a `BUILD` file ends up in there somehow, it'll confuse kazel and generate invalid entries in top-level `BUILD` files that we do check in. We can avoid this issue by instructing kazel to ignore these directories.
**Release note**:
```release-note
NONE
```
/assign @mikedanese @thockin @BenTheElder
1ac21b75c4