Bumping gaia.json for 4 gaia-central revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/3136a3840ace
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #15183 from alivedise/bugzilla/948226/activity-orientation-lock

Bug 948226 - Activity orientation lock order, r=timdream

========

https://hg.mozilla.org/integration/gaia-central/rev/b974a9e1970e
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 948226 - Activity orientation lock order

========

https://hg.mozilla.org/integration/gaia-central/rev/3c40f1d0b1f7
Author: EragonJ <eragonj@eragonj.me>
Desc: Merge pull request #14953 from EragonJ/bug-949982

Bug 949982 - [Gaia][DSDS] Fine tune SIM manager UI

========

https://hg.mozilla.org/integration/gaia-central/rev/38c1f53e6557
Author: EragonJ <eragonj@eragonj.me>
Desc: Bug 949982 - [Gaia][DSDS] Fine tune SIM manager UI