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

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https://hg.mozilla.org/integration/gaia-central/rev/49a63b8e54ca
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Merge pull request #13829 from zacc/bug_930052_6

Bug 935052 - Reduce exposure to launch() method inside tests.

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https://hg.mozilla.org/integration/gaia-central/rev/cb9ac9d0bbd3
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 930052 - Reduce exposure to launch() method inside tests.