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

========

https://hg.mozilla.org/integration/gaia-central/rev/5c524bba1fbf
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #12039 from comoyo/supports-switching

Bug 912951 - Send content event from gaia -> chrome with layout info for supportsSwitching

========

https://hg.mozilla.org/integration/gaia-central/rev/a52e4fd748bc
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Bug 912951 - Send content event from gaia -> chrome with layout info for supportsSwitching