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

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https://hg.mozilla.org/integration/gaia-central/rev/334f11f61c9a
Author: Margaret Leibovic <margaret.leibovic@gmail.com>
Desc: Merge pull request #18842 from darchons/bug864395-the-i-want-to-help

Bug 864395 - Correctly test send perf data checkbox;

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https://hg.mozilla.org/integration/gaia-central/rev/957368d4acc8
Author: Jim Chen <nchen@mozilla.com>
Desc: Bug 864395 - Correctly test send perf data checkbox;
Bumping manifests a=b2g-bump