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

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https://hg.mozilla.org/integration/gaia-central/rev/16672d155555
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #18705 from TheoChevalier/merge-test-locales-2.0-dev

[Bug 1001220] [l10n][2.0] Merge test locales in Github for developers

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https://hg.mozilla.org/integration/gaia-central/rev/00480ca3a62b
Author: TheoChevalier <theo.chevalier11@gmail.com>
Desc: [Bug 1001220] [l10n][2.0] Merge test locales in Github for developers
Bumping manifests a=b2g-bump