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

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https://hg.mozilla.org/integration/gaia-central/rev/3e7b6feeeade
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #11328 from jimporter/music-fix-mediadb

Bug 901309 - Fix issues with device storage in mediadb.js

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https://hg.mozilla.org/integration/gaia-central/rev/c21987e9671c
Author: Jim Porter <jporter@mozilla.com>
Desc: Bug 901309 - Fix issues with device storage in mediadb.js

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "25f044f2ab1542ab4e015f67f0f256252cf28e67", 
+    "revision": "3e7b6feeeadedc472368ecad65016a6df75570f5", 
     "repo_path": "/integration/gaia-central"
 }