Update Gaia API documents for #6815158274fe7951ca7a092600027593f4302243
    Merge pull request #15163 from millermedeiros/951423-header-truncated

Bug 951423 - [B2G][Calendar][Day View]Header displays truncated if date exceeds eighteen characters.
(cherry picked from commit 61797fd7cf908f13f140b98f94ace038e2321c05)