docs: Removed broken link to non-existent method.

Doc had included link to method MediaBrowserService.onLoadIcon().
Per bug http://b/17205016 that method was removed before release.

Revised doc is staged to:

http://asolovay.mtv.corp.google.com:9650/reference/android/service/media/MediaBrowserService.Result.html

(Note that the other "See Also" link, which I didn't remove, is badly
formatted because Javadoc seems to choke on links to methods that are
passed generic types. JoeFernandez@, if you can suggest a better way
to format that link I'll make that change too.)

bug: 18229650
Change-Id: Ic55ae8b9edc6dd314cf5acc306abd8a9d5f71134