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

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https://hg.mozilla.org/integration/gaia-central/rev/a98c1c4a288a
Author: Dave Hylands <dhylands@gmail.com>
Desc: Merge pull request #20098 from dhylands/bug-986331-3g2

Bug 986331 - Add support for .3g2 file extension (maps to video/3gpp2 mime type) r=djf

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https://hg.mozilla.org/integration/gaia-central/rev/e4eba407bd07
Author: Dave Hylands <dhylands@gmail.com>
Desc: Bug 986331 - Add support for .3g2 file extension (maps to video/3gpp2 mime type)
Bumping manifests a=b2g-bump