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

========

https://hg.mozilla.org/integration/gaia-central/rev/0b3218bb00b1
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Merge pull request #15295 from wilsonpage/bug/959301

Bug 959301 - [B2G][Camera] Taking photo from lockscreen without passcode...

========

https://hg.mozilla.org/integration/gaia-central/rev/47200d5a3e24
Author: Wilson Page <wilsonpage@me.com>
Desc: Bug 959301 - [B2G][Camera] Taking photo from lockscreen without passcode displays Retake and Select buttons on UI