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

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https://hg.mozilla.org/integration/gaia-central/rev/b859207fe404
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #19477 from steveck-chung/bug-1003820

Bug 1003820 - [Messages] Recipients container grows without limit breaking the layout. r=julienw

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https://hg.mozilla.org/integration/gaia-central/rev/72a245a5ab6f
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 1003820 - [Messages] Recipients container grows without limit breaking the layout
Bumping manifests a=b2g-bump