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

========

https://hg.mozilla.org/integration/gaia-central/rev/edc0c2f7ca48
Author: Sam Joch <samuel@guiora.com>
Desc: Merge pull request #12335 from pivanov/bug-906830

Bug 906830 - [Camera] HD grey circle buttons look fuzzy r=samjoch

========

https://hg.mozilla.org/integration/gaia-central/rev/4c93c9cb67df
Author: Pavel Ivanov <pivanov@mozilla.com>
Desc: Bug 906830 - [Camera] HD grey circle buttons look fuzzy