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

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https://hg.mozilla.org/integration/gaia-central/rev/844b31f878fa
Author: James Lal <james@lightsofapollo.com>
Desc: Merge pull request #20187 from KevinGrandon/bug_1022131_take_2

Bug 1022131 - Intermittent Marionette JS Failure on Travis: Statusbar Scrolling > The statusbar changes the appearance properly

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https://hg.mozilla.org/integration/gaia-central/rev/56bf8a5770de
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1022131 - Intermittent Marionette JS Failure on Travis: Statusbar Scrolling > The statusbar changes the appearance properly
Bumping manifests a=b2g-bump