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

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https://hg.mozilla.org/integration/gaia-central/rev/99a2a0102ace
Author: Ran Ben Aharon <ran@everything.me>
Desc: Merge pull request #12466 from crdlc/bug-910334

Bug 910334 - [e.me][feature] Update icon to drag apps into collections and the white circle behind them

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https://hg.mozilla.org/integration/gaia-central/rev/14810c33161f
Author: crdlc <crdlc@tid.es>
Desc: Bug 910334 - [e.me][feature] Update icon to drag apps into collections and the white circle behind them