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

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https://hg.mozilla.org/integration/gaia-central/rev/e4b16d4bbb51
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #25362 from Cwiiis/bug1085550-fix-group-collapse-test

Bug 1085550 - Fix verticalhome group_collapse_test.js. r=kgrandon

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https://hg.mozilla.org/integration/gaia-central/rev/864d177baacc
Author: Chris Lord <chrislord.net@gmail.com>
Desc: Bug 1085550 - Fix verticalhome group_collapse_test.js. r=kgrandon
Bumping manifests a=b2g-bump