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

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https://hg.mozilla.org/integration/gaia-central/rev/49936812396c
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #17682 from alivedise/bugzilla/988261/hide-utility-tray-on-launchapp

Bug 988261 - Hide utility tray on launchapp event, r=timdream

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https://hg.mozilla.org/integration/gaia-central/rev/e386af213862
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 988261 - Hide utility tray on launchapp event
Bumping manifests a=b2g-bump