Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_0/rev/4182f4d627ee
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Merge pull request #21199 from dmarcos/bug1024692master

Bug 1024692: limit image decode size to 3mp on 256mb devices
Bumping manifests a=b2g-bump