Update Gaia API documents for #27f6ac2b5591dace72951baebde2345422b6f1e5
    Merge pull request #14836 from EragonJ/bug-948847

Bug 948847 - [Gaia] add AirplaneModeHelper to make sure settings app and system app will not do the same thing
(cherry picked from commit 1bd937c8c110788fcaec7deefe5f3367def18a42)