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

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https://hg.mozilla.org/integration/gaia-central/rev/fb0ad147657a
Author: Carsten Book <tomcat@mozilla.com>
Desc: Merge pull request #23989 from mancas/bug1065062

[Settings][Downloads] "Select/Deselect All" buttons are missing from Dow... r=arthur.chen

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https://hg.mozilla.org/integration/gaia-central/rev/9eb6dd5c00d2
Author: Manuel Casas Barrado <manuel.casasbarrado@telefonica.com>
Desc: Bug 1065062 - [Settings][Downloads] 'Select/Deselect All' buttons are missing from Downloads Edit page. r=arthur.chen
Bumping manifests a=b2g-bump