Add huawei cloud controller (#10198)

* Add huaweicloud as external cloud controller

* Add huaweicloud example config

* Rename AK,SK to ACCESS_KEY and SECRET_KEY

* Add reference to huaweicloud

* Fix variable naming

* Fix env var name

* Update example

* Fix variable naming

* Fix cloud_config path

* Add namespace for leader election

* Revert reviewers

* Delete OWNERS

Delete owners who are not responsible here.

* Fix build validation