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

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https://hg.mozilla.org/integration/gaia-central/rev/a15825c71d6b
Author: George <georgeiscoming@gmail.com>
Desc: Merge pull request #16079 from cctuan/968671

Bug 968671 - Modify Makefile for camera app to migrate camera related code from applications-data.js

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https://hg.mozilla.org/integration/gaia-central/rev/7eba440a02a2
Author: cctuan <georgeiscoming@gmail.com>
Desc: Bug 968671 - Modify Makefile for camera app to migrate camera related code from applications-data.js

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "25d6f0f7e2b994b499ae2e5c6971a5f932d94c44", 
+    "revision": "a15825c71d6b6146e466944e52a242508995dc9b", 
     "repo_path": "/integration/gaia-central"
 }