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

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https://hg.mozilla.org/integration/gaia-central/rev/1d7a49e94c98
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #19014 from KevinGrandon/bug_971443_system2_accessibility

Bug 971443 - [System2] Instantiable Accessibility

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https://hg.mozilla.org/integration/gaia-central/rev/41ba942afebb
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 971443 - [System2] Instantiable Accessibility r=alive
Bumping manifests a=b2g-bump