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

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https://hg.mozilla.org/integration/gaia-central/rev/138d0f2c4d3a
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #11715 from crh0716/891743

Bug 891743 - Add voice privacy mode for CDMA r=evelyn

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https://hg.mozilla.org/integration/gaia-central/rev/de97091310f0
Author: Arthur Chen <crh0716@gmail.com>
Desc: Bug 891743 - Add voice privacy mode for CDMA