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

========

https://hg.mozilla.org/integration/gaia-central/rev/f6556c09eb6c
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #20841 from KevinGrandon/bug_839491_unrecoverable_app_install

Bug 839491 - Handle unrecoverable app installs from the homescreen/search/collections apps

========

https://hg.mozilla.org/integration/gaia-central/rev/8067c03cac21
Author: James Lal <james@lightsofapollo.com>
Desc: Bug 839491 - Handle unrecoverable app installs from the homescreen/search/collections apps r=kgrandon

b2g/config/gaia.json

@@ -4,6 +4,6 @@
         "remote": "", 
         "branch": ""
     }, 
-    "revision": "1cbab43be1643d4dbea2183dea4c1646741af6c0", 
+    "revision": "f6556c09eb6c0e2152de2f880a0d41245e8408c1", 
     "repo_path": "/integration/gaia-central"
 }