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

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https://hg.mozilla.org/integration/gaia-central/rev/428cccdc7a3b
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #14305 from crdlc/bug-945628

Bug 945628 - [Download Manager] Discover storage name and relative path ...

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https://hg.mozilla.org/integration/gaia-central/rev/f1fc57d12fa6
Author: crdlc <crdlc@tid.es>
Desc: Bug 945628 - [Download Manager] Discover storage name and relative path from absolute paths