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

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https://hg.mozilla.org/integration/gaia-central/rev/f216f6f4b028
Author: George <georgeiscoming@gmail.com>
Desc: Merge pull request #13434 from cctuan/934906

Bug 934906 - [Flatfish] Dock disappears

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https://hg.mozilla.org/integration/gaia-central/rev/3b3fc4049aad
Author: cctuan <georgeiscoming@gmail.com>
Desc: Bug 934906 - [Flatfish] Dock disappears