Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/9420e20475da
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Revert "Bug 1078901 - Confirmation dialog when deleting apps blocks notfications and software home button. r=kgrandon"

This reverts commit a82fc6ec2da3667793065469c8b75de20cb8834a.
Bumping manifests a=b2g-bump