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

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https://hg.mozilla.org/integration/gaia-central/rev/5bb0222b01cd
Author: vingtetun <21@vingtetun.org>
Desc: Merge pull request #15688 from vingtetun/bug961047

Bug 961047 - Remove some dead code in Gaia with APZC enabled by default ...

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https://hg.mozilla.org/integration/gaia-central/rev/1e8e6f992756
Author: Vivien Nicolas <21@vingtetun.org>
Desc: Bug 961047 - Remove some dead code in Gaia with APZC enabled by default from the platform. r=alive,fabrice
Bumping manifests a=b2g-bump