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

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https://hg.mozilla.org/integration/gaia-central/rev/522521ec4e42
Author: Rudy Lu <me@rudy.lu>
Desc: Merge pull request #19242 from RudyLu/ime/Bug991052

Bug 991052 - keyboard layout switch function is not
r=alive.

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https://hg.mozilla.org/integration/gaia-central/rev/b6718f589480
Author: Rudy Lu <me@rudy.lu>
Desc: Bug 991052 - keyboard layout switch function is not available in utility
tray.
 - Do preventDefault for mousdown event on statusbar.
Bumping manifests a=b2g-bump