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

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https://hg.mozilla.org/integration/gaia-central/rev/47daabb93939
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #11516 from leob2g/Bug_901801_897874_Followup_Notification_horizontally_scrollable_with_many_CB_messages

Bug 901801 - 897874 Followup: [Notification] horizontally scrollable with many CB messages, r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/8bc21763cb22
Author: hanj.kim <hanj.kim@lge.com>
Desc: Bug 901801 - 897874 Followup: [Notification] horizontally scrollable with many CB messages