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

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https://hg.mozilla.org/integration/gaia-central/rev/84ef43784804
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #12361 from zacc/bug919507

Bug 919507 - Disable test_browser_search

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https://hg.mozilla.org/integration/gaia-central/rev/3f971ad96782
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 919515 - Disable test_browser_search - Searching for words is not giving results