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

========

https://hg.mozilla.org/integration/gaia-central/rev/1fff1ba9259b
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #12649 from etiennesegonzac/bug-920940-call-direction

Bug 920940 - Fixing a regression where the "direction" of the call wasn't displayed. r=rik

========

https://hg.mozilla.org/integration/gaia-central/rev/27dda8bc5d20
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 920940 - Fixing a regression where the "direction" of the call
wasn't displayed.
r=rik