Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/bb575a64b77d
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Bug 1097556 - Correctly expose cs-qwerty layout, r=me
Bumping manifests a=b2g-bump