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

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https://hg.mozilla.org/integration/gaia-central/rev/fd402808a1ba
Author: Jared Hirsch <ohai@6a68.net>
Desc: Merge pull request #19652 from 6a68/bug-1010598-remove-coppa-fxa-fte

Bug 1010598 - Remove COPPA screen from FxA FTE flow

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https://hg.mozilla.org/integration/gaia-central/rev/46c3bb4f6e65
Author: Jared Hirsch <ohai@6a68.net>
Desc: Bug 1010598 - Remove COPPA screen from FxA FTE flow. r=ferjm
Bumping manifests a=b2g-bump