Bumping gaia.json for 2 gaia-central revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/8974a0511dc3
Author: Jose M. Cantera <jmcanterafonseca@gmail.com>
Desc: Merge pull request #13069 from gtorodelvalle/contacts-bug-925307-intro-exits-search-mode-reloaded

Bug 925307 - [Contacts] In search mode, clicking ENTER on the keyboard exits the search mode (follow-up)

========

https://hg.mozilla.org/integration/gaia-central/rev/605838645515
Author: Germán Toro del Valle <gtorodelvalle@gmail.com>
Desc: Bug 925307 - [Contacts] In search mode, clicking ENTER on the keyboard exits the search mode (follow-up)