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

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https://hg.mozilla.org/integration/gaia-central/rev/bae156eafe93
Author: Evyatar Amitay <evyatron@gmail.com>
Desc: Merge pull request #12688 from EverythingMe/923899-clear-button

[Bug 923899] Fix clear button clickable area [r=ranbena]

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https://hg.mozilla.org/integration/gaia-central/rev/4498a6e5916e
Author: Evyatar Amitay <evyatron@gmail.com>
Desc: [Bug 923899] Fix clear button clickable area [r=ranbena]