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

========

https://hg.mozilla.org/integration/gaia-central/rev/8b27163b57ee
Author: John Hu <johu@mozilla.com>
Desc: Merge pull request #14455 from ethantseng/rtsp/bug928332

Bug 928332 - [RTSP][Gaia] Support RTSP in Video apps., r=johnhu

========

https://hg.mozilla.org/integration/gaia-central/rev/fc93ae5539c6
Author: Ethan Tseng <ettseng@mozilla.com>
Desc: Bug 928332 - [RTSP][Gaia] Support RTSP in Video apps.