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

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https://hg.mozilla.org/integration/gaia-central/rev/3a9654733e58
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Merge pull request #18198 from mcav/power-snooze

 Bug 996092 - [Clock] Use hardware buttons to dismiss/mute alarms. r=millermedeiros

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https://hg.mozilla.org/integration/gaia-central/rev/7a5feee904f7
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Bug 996092 - [Clock] Use hardware buttons to dismiss/mute alarms. r=millermedeiros
Bumping manifests a=b2g-bump