Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_0/rev/ce9a0e9015f1
Author: DouglasSherk <github@sherk.me>
Desc: Bug 1019546 - [Visual Refresh][Dialer] Fix dial pad and contacts overlapping when being switched between. r=rik