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

========

https://hg.mozilla.org/integration/gaia-central/rev/4624f54b8c38
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #17012 from echangmoz/master

Bug 980811 - Change Fugu device ID

========

https://hg.mozilla.org/integration/gaia-central/rev/c72475aaf01f
Author: ericcc <echangmoz@mozilla.com>
Desc: Change Fugu device ID
Bumping manifests a=b2g-bump