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

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https://hg.mozilla.org/integration/gaia-central/rev/70ee4748ef86
Author: John Hu <johu@mozilla.com>
Desc: Merge pull request #13373 from huchengtw-moz/video/Bug_929801_date_locale

Bug 929801 - [B2G][1.2][l10n][Video] Videos’ time stamps are not transla..., r=djf

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https://hg.mozilla.org/integration/gaia-central/rev/6c09cca35e51
Author: John Hu <johu@mozilla.com>
Desc: Bug 929801 - [B2G][1.2][l10n][Video] Videos’ time stamps are not translated in multiple languages when viewed in the Video App.