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

========

https://hg.mozilla.org/integration/gaia-central/rev/4c17313c6f22
Author: Fabrice Desré <fabrice@desre.org>
Desc: Merge pull request #15173 from fabricedesre/adb-debug-only

Bug 956185 - Add a 'adb only' debugging option r=kaze

========

https://hg.mozilla.org/integration/gaia-central/rev/a29eec4d4061
Author: Fabrice Desre <fabrice@desre.org>
Desc: Bug 956185 - Add a 'adb only' debugging option r=kaze