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

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https://hg.mozilla.org/integration/gaia-central/rev/6debe3af1446
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #13375 from crh0716/911701_1

Bug 911701 - Show data signal strength when connecting to EVDO r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/f8b6c92cacab
Author: Arthur Chen <crh0716@gmail.com>
Desc: Bug 911701 - Show data signal strength when connecting to EVDO