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

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https://hg.mozilla.org/integration/gaia-central/rev/198e6ff0d117
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #21444 from alivedise/bugzilla/1027401_v2.1/reset-orientation-on-popupclose

Bug 1027401 - Change child event mechanism, r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/7b16e55f0aba
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 1027401 - Change child event mechanism
Bumping manifests a=b2g-bump