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

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https://hg.mozilla.org/integration/gaia-central/rev/d276d31ff93f
Author: Ismael González <ismael@basiclines.com>
Desc: Merge pull request #11069 from basiclines/costcontrol-fixes

Bug 894200 - [Usage] Progress indicator need to update to new BB or @1.5x assets of old version

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https://hg.mozilla.org/integration/gaia-central/rev/bfe458626777
Author: basiclines <igonzaleznicolas@gmail.com>
Desc: Bug 894200 - [Usage] Progress indicator need to update to new BB or @1.5x assets of old version