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

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https://hg.mozilla.org/integration/gaia-central/rev/10421ab443a8
Author: Casey Yee <cyee@mozilla.com>
Desc: Merge pull request #14437 from caseyyee/bug-929361

Bug 929361 - [Keyboard] Update Keyboard Visual Design

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https://hg.mozilla.org/integration/gaia-central/rev/1e479159a8ba
Author: Casey Yee <casey@caseyyee.com>
Desc: Bug 929361 - [Keyboard] Update Keyboard Visual Design