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

========

https://hg.mozilla.org/integration/gaia-central/rev/a02b3256fc6c
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #13458 from gasolin/issue-930306

Bug 930306 - [Flatfish][System] system wrongly change the orientation ca..., r=alive

========

https://hg.mozilla.org/integration/gaia-central/rev/225aa4cd6849
Author: gasolin <gasolin@gmail.com>
Desc: Bug 930306 - [Flatfish][System] system wrongly change the orientation cause homescreen grid get wrong width