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

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https://hg.mozilla.org/integration/gaia-central/rev/9f96af5a6624
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #16559 from timdream/keyboard2-keyboard

Bug 975963 - Split keyboard.js into instancable KeyboardApp() and boot.js, r=rudyl

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https://hg.mozilla.org/integration/gaia-central/rev/28af01faecb1
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Bug 975963 - Split keyboard.js into instancable KeyboardApp() and boot.js
Bumping manifests a=b2g-bump