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

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https://hg.mozilla.org/integration/gaia-central/rev/edd247149d8c
Author: Ran Ben Aharon <ran@everything.me>
Desc: Merge pull request #12675 from EverythingMe/bugfix-923701

Bug 923701 - [B2G][Homescreen] Collection icons appear offset when they are in the Dock [r=crdlc]

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https://hg.mozilla.org/integration/gaia-central/rev/990d42025f26
Author: Ran Ben Aharon <ran@ranbena.com>
Desc: Bug 923701 - [B2G][Homescreen] Collection icons appear offset when they are in the Dock [r=crdlc]