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

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https://hg.mozilla.org/integration/gaia-central/rev/d12b81be5b2d
Author: Andrew Halberstadt <halbersa@gmail.com>
Desc: Merge pull request #21788 from ahal/gi_manifests

Bug 1039140 - Add manifestparser style manifests for gaia-integration, r...

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https://hg.mozilla.org/integration/gaia-central/rev/02bc23c1732a
Author: Andrew Halberstadt <halbersa@gmail.com>
Desc: Bug 1039140 - Add manifestparser style manifests for gaia-integration, r=mdas
Bumping manifests a=b2g-bump