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

========

https://hg.mozilla.org/integration/gaia-central/rev/88749495288f
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #16032 from KevinGrandon/bug_968382_software_buttons_level

Bug 968382 - software home button doesn't work when rocketbar is active r=alive

========

https://hg.mozilla.org/integration/gaia-central/rev/b6d05b54a998
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 968382 - software home button doesn't work when rocketbar is active r=alive
Bumping manifests a=b2g-bump