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

========

https://hg.mozilla.org/integration/gaia-central/rev/0c0dfba36634
Author: Pavel Ivanov <pivanov@mozilla.com>
Desc: Merge pull request #17161 from pivanov/bug-968483

Bug 968483 - [Building Blocks] Update header design to accommodate larger back-button

========

https://hg.mozilla.org/integration/gaia-central/rev/307079877934
Author: Pavel Ivanov <pivanov@mozilla.com>
Desc: Bug 968483 - [Building Blocks] Update header design to accommodate larger back-button
Bumping manifests a=b2g-bump
Merge m-c to b2g-inbound.
Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/04a13c212e02
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #17139 from julienw/947139-send-default-sim

Bug 947139 - [DSDS][Message] Send message via default SIM r=schung

========

https://hg.mozilla.org/integration/gaia-central/rev/baf554253a9e
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 947139 - [DSDS][Message] Send message via default SIM r=francisco

This refactors the sendSMS and sendMMS methods in MessageManager, and passes the
serviceId all the way from the UI to the API.

This also styles the composer for DSDS configurations, and display the correct
SIM inside the button.
Bumping manifests a=b2g-bump