Bumping gaia.json for 1 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/7d2cf0d6f8cb
Author: Mike Pennisi <mike@mikepennisi.com>
Desc: Revert "Bug 898666 - [clock] Clock refactor alarm object and add test"

This reverts commit 3746b1cdc0e344460c58cd52f85564b0c4f5940a due to a
UI regression in the ordering of Alarm list items.