All functions in the API-MS-Win-Service-Management-L1-1-0 set are documented exports from ADVAPI32:

The implementations in ADVAPI32 version 6.1 and higher are just stubs which transfer the handling to wherever the schema redirects the API Set.

New Locations

Non-trivial implementations of all functions in this API Set are exported from SECHOST version 6.1 and higher.

Schema Redirection

The Windows 7 schema redirects this API Set to SECHOST. Thus: