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

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https://hg.mozilla.org/integration/gaia-central/rev/3018addb2346
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #25551 from KevinGrandon/bug_1088462_statusbar_activity_width

Bug 1088462 - [System] Adjust statusbar min width on activityopened

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https://hg.mozilla.org/integration/gaia-central/rev/4af90413e012
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1088462 - [System] Adjust statusbar min width on activityopened r=etienne
Bumping manifests a=b2g-bump