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

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https://hg.mozilla.org/integration/gaia-central/rev/8b2eef7e5d6b
Author: Jared Hirsch <ohai@6a68.net>
Desc: Merge pull request #19793 from 6a68/bug-1017152-fxa-coppa-select-css

Bug 1017152 - COPPA screen select element label misaligned

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https://hg.mozilla.org/integration/gaia-central/rev/a34f9f3519dd
Author: Jared Hirsch <ohai@6a68.net>
Desc: Bug 1017152 - COPPA screen select element label misaligned. r=ferjm
Bumping manifests a=b2g-bump