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

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https://hg.mozilla.org/integration/gaia-central/rev/20224d644054
Author: Ricky Chien <ricky060709@gmail.com>
Desc: Merge pull request #26985 from RickyChien/bug-1112748

Bug 1112748 - Do not install horizontal home screen onto devices r=@cctuan

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https://hg.mozilla.org/integration/gaia-central/rev/e9ad13a6ce97
Author: Ricky Chien <ricky060709@gmail.com>
Desc: Bug 1112748 - Do not install horizontal home screen onto devices
Bumping manifests a=b2g-bump