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

========

https://hg.mozilla.org/integration/gaia-central/rev/a6b6fd3772ee
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #25144 from KevinGrandon/bug_1082683_fte_test_structure

Bug 1082683 - [FTE] Integration test structure

========

https://hg.mozilla.org/integration/gaia-central/rev/8d1dc1481c8f
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1082683 - [FTE] Integration test structure r=sfoster
Bumping manifests a=b2g-bump