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

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https://hg.mozilla.org/integration/gaia-central/rev/d253e50da6b5
Author: Arnau <arnau@arnaumarch.com>
Desc: Merge pull request #18424 from rnowm/997414

Bug 997414 - [VDR][Clock] Apply new Buttons and Inputs [BB] r=mcav

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https://hg.mozilla.org/integration/gaia-central/rev/3643c4eb9bd7
Author: rnowm <arnau@arnaumarch.com>
Desc: Bug 997414 - [VDR][Clock] Apply new Buttons and Inputs [BB]
Bumping manifests a=b2g-bump