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

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https://hg.mozilla.org/integration/gaia-central/rev/3d5a26530878
Author: Hubert Figuière <hub@figuiere.net>
Desc: Merge pull request #18952 from hfiguiere/bug1005917

Bug 1005917 - Detect the role of the app to autoskip.  r=julienw

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https://hg.mozilla.org/integration/gaia-central/rev/4f7d3aa8b256
Author: Hubert Figuière <hub@figuiere.net>
Desc: Bug 1005917 - Detect the role of the app to autoskip. r=julienw
Bumping manifests a=b2g-bump