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

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https://hg.mozilla.org/integration/gaia-central/rev/290d2aaaa650
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #12025 from gasolin/issue-907075

907075 - [Permission] Dismiss continuous same permission request but dis..., r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/710230e47727
Author: gasolin <gasolin@gmail.com>
Desc: 907075 - [Permission] Dismiss continuous same permission request but dispatch mozContentEvent as well if remember is checked

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "175bcf94c3ff3aab3e5d0bdaf05427602f658406", 
+    "revision": "290d2aaaa650f342644a55bfbaead06e1b899107", 
     "repo_path": "/integration/gaia-central"
 }