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

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https://hg.mozilla.org/integration/gaia-central/rev/8270d650d4dd
Author: Sam Joch <samuel@guiora.com>
Desc: Merge pull request #10006 from pivanov/bug-835842

Bug 835842 - [Calendar UX VD] Use BB for Tabs, the have wrong hit state and odd style r=samjoch

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https://hg.mozilla.org/integration/gaia-central/rev/9d3242356641
Author: Pavel Ivanov <pivanov@mozilla.com>
Desc: Bug 835842 - [Calendar UX VD] Use BB for Tabs, the have wrong hit state and odd style