Remove Rest admin permissions feature from 2.x branch 

The feature added in https://github.com/opensearch-project/security/pull/2411 requires a security review, and until this has been completed, it should not be included in any releases.  We can ensure this by removing the feature from the 2.x and/or the 2.7 branch if it has been created.

- https://github.com/opensearch-project/security/issues/2632