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

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https://hg.mozilla.org/integration/gaia-central/rev/30d1ae1b649c
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #15380 from KevinGrandon/bug_891882_enable_edge_gesture_test

Bug 891882 - Enable edge gesture test

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https://hg.mozilla.org/integration/gaia-central/rev/6c258986f20b
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 891882 - Enable edge gesture test