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

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https://hg.mozilla.org/integration/gaia-central/rev/d12b645e3b8b
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #14779 from mvines/bug950809

Bug 950809 - Add null check for e.accelerationIncludingGravity. r=johnhu

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https://hg.mozilla.org/integration/gaia-central/rev/d6423ca5d324
Author: Michael Vines <mvines@codeaurora.org>
Desc: Bug 950809 - Add null check for e.accelerationIncludingGravity. r=johnhu