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

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https://hg.mozilla.org/integration/gaia-central/rev/630807a63833
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Merge pull request #18118 from comoyo/bug993999

Bug 993999 - Move keyboard iframes that are not needed of screen, instead of hidden, to avoid all content to reflow when showing again. r=RudyL

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https://hg.mozilla.org/integration/gaia-central/rev/a605812d54d3
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Bug 993999 - Move keyboard iframes that are not needed of screen, instead of hidden, to avoid all content to reflow when showing again
Bumping manifests a=b2g-bump