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

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https://hg.mozilla.org/integration/gaia-central/rev/fc77f096dd97
Author: Sherman Chen <shamenchens@users.noreply.github.com>
Desc: Merge pull request #26709 from shamenchens/Bug1110037-DeviceSpecificWallpaper

Bug 1110037 - Device specific wallpaper, r=RickyChien

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https://hg.mozilla.org/integration/gaia-central/rev/11926c74649a
Author: Sherman Chen <shamen.chens@gmail.com>
Desc: Bug 1110037 - Device specific wallpaper
Bumping manifests a=b2g-bump