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

========

https://hg.mozilla.org/integration/gaia-central/rev/6d1272d06cdc
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #14601 from alivedise/bugzilla/948866/better-homescreen-opening-transition

Bug 948866 - Smooth homescreen opening transition, r=etienne

========

https://hg.mozilla.org/integration/gaia-central/rev/811faa69b71e
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 948866 - Smooth homescreen opening transition