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

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https://hg.mozilla.org/integration/gaia-central/rev/f2d8e20acf0b
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #13163 from dwi2/bug907625

Bug 907625 - Prevent keyboard blocks incoming callscreen when keyboard i...,r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/fedd94184c12
Author: tzhuang <tzhuang@mozilla.com>
Desc: Bug 907625 - Prevent keyboard blocks incoming callscreen when keyboard is on