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

========

https://hg.mozilla.org/integration/gaia-central/rev/4073b397d7b5
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #20906 from guilherme-pg/bug947985-fmd-icon

Bug 947985 - Include final icon for Find My Device.

========

https://hg.mozilla.org/integration/gaia-central/rev/7938357322c0
Author: Guilherme Goncalves <guilherme.p.gonc@gmail.com>
Desc: Bug 947985 - Include final icon for Find My Device.

b2g/config/gaia.json

@@ -4,6 +4,6 @@
         "remote": "", 
         "branch": ""
     }, 
-    "revision": "6aa12aaf308697cc4a8f8f5a4c134eaba6cc6294", 
+    "revision": "4073b397d7b5d37ae81ced569e4af7c734defe68", 
     "repo_path": "/integration/gaia-central"
 }