Bumping gaia.json for 1 gaia-1_3 revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-1_3/rev/dcad6b07b412
Author: Michael Vines <mvines@codeaurora.org>
Desc: Bug 950809 - Add null check for e.accelerationIncludingGravity. r=johnhu