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

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https://hg.mozilla.org/integration/gaia-central/rev/6cbf012fc0dc
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #14862 from KevinGrandon/rocketbar_disable_failing_test

Bug 946452 - Disable rocketbar failing tests r=me

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https://hg.mozilla.org/integration/gaia-central/rev/7792734c96f2
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 946452 - Disable rocketbar failing tests r=me