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

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https://hg.mozilla.org/integration/gaia-central/rev/8b9db1277c4f
Author: vingtetun <21@vingtetun.org>
Desc: Merge pull request #23537 from vingtetun/camera.less.overpaint

Bug 1059157 - Reduce the overpaint of the camera app. r=jdarcangelo

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https://hg.mozilla.org/integration/gaia-central/rev/c1525e360e8d
Author: Vivien Nicolas <vnicolas@mozilla.com>
Desc: Bug 1059157 - Reduce the overpaint of the camera app. r=jdarcangelo
Bumping manifests a=b2g-bump