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

========

https://hg.mozilla.org/integration/gaia-central/rev/a824661b8338
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #13146 from caiolima/bug_815093

Bug 815093 - Compose "new" activities are unable to return to calling app once message is sent

========

https://hg.mozilla.org/integration/gaia-central/rev/8829732fae72
Author: Caio Lima <ticaiolima@gmail.com>
Desc: Bug 815093 - Compose activities returning to caller app r=julien

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "2cfbe5852250d20a8793d5ebed7684dae7e6444d", 
+    "revision": "a824661b83388d17f80c28a1d538eae382b3d07d", 
     "repo_path": "/integration/gaia-central"
 }