Updated title to "API Reference" from "Dev Guide" for consistency

bug: #1178388

Change-Id: I24b2ac9e4d6ceebd56ab2ff8bc23f298349cc1fe
author: diane fleming
Update title to "API Reference" from "Developer Guide" for consistency

Change-Id: I3f7edb40c51ecbf7d5a53e8c1e3c7add7a7ea015
author: diane fleming