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

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https://hg.mozilla.org/integration/gaia-central/rev/75365f3376da
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #20609 from nullaus/bug1024397

bug 1024397 - Hide value selector when receiving 'activityclosing'. r=al...

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https://hg.mozilla.org/integration/gaia-central/rev/11d4901753e8
Author: Ghislain 'Aus' Lacroix <aus@mozilla.com>
Desc: bug 1024397 - Hide value selector when receiving 'activityclosing'. r=alive
Bumping manifests a=b2g-bump