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

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https://hg.mozilla.org/integration/gaia-central/rev/ff5e5b9be494
Author: Arnau <arnau@arnaumarch.com>
Desc: Merge pull request #19020 from pacorampas/buttons-settings-1003817

Bug 1003817 - [BB] Buttons: update list button to new specs r=me

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https://hg.mozilla.org/integration/gaia-central/rev/e71d94a4f483
Author: Paco Rampas <pacorampas@gmail.com>
Desc: Bug 1003817 - [BB] Buttons: update list button to new specs
Bumping manifests a=b2g-bump