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

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https://hg.mozilla.org/integration/gaia-2_1/rev/b84725a51236
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1068442 - Add marionette test for SHB on secure window r=alive

Conflicts:
	apps/system/test/marionette/lib/system.js
Bumping manifests a=b2g-bump