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

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https://hg.mozilla.org/integration/gaia-central/rev/567a1121b9a1
Author: Chris Lord <chrislord.net@gmail.com>
Desc: Merge pull request #24576 from Cwiiis/bug1074993-app-grouping-group-headers

Bug 1074993 - Update group headers to match spec. r=kgrandon

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https://hg.mozilla.org/integration/gaia-central/rev/ae4249334ffd
Author: Chris Lord <chrislord.net@gmail.com>
Desc: Bug 1074993 - Update group headers to match spec. r=kgrandon
Bumping manifests a=b2g-bump