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

========

https://hg.mozilla.org/integration/gaia-central/rev/9d8726c8d60a
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #22372 from nullaus/bug1046565

bug1046565 - Add system.png 60x60 for notification purposes. Update refe...

========

https://hg.mozilla.org/integration/gaia-central/rev/9c04011db2bc
Author: Ghislain 'Aus' Lacroix <aus@mozilla.com>
Desc: bug1046565 - Add system.png 60x60 for notification purposes. Update references from System.png to system.png. r=kgrandon
Bumping manifests a=b2g-bump