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

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https://hg.mozilla.org/integration/gaia-central/rev/336bb1363ec1
Author: EragonJ <eragonj@eragonj.me>
Desc: Merge pull request #20404 from EragonJ/bug-968677

Bug 968677 - [settings] add marionette test for Messaging Settings panel

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https://hg.mozilla.org/integration/gaia-central/rev/9efb8cc11c11
Author: EragonJ <eragonj@eragonj.me>
Desc: Bug 968677 - [settings] add marionette test for Messaging Settings panel
Bumping manifests a=b2g-bump