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

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https://hg.mozilla.org/integration/gaia-central/rev/80f61408b2c8
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #16729 from nullaus/bug976960

bug 976960

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https://hg.mozilla.org/integration/gaia-central/rev/c4f2d6ed009f
Author: Ghislain 'Aus' Lacroix <aus@mozilla.com>
Desc: bug 976960

* fire cardviewclosed with new stack position but wait for 'appopen' from AppWindowManager to fire before actually hiding the cardswitcher.
* added unit test to ensure that we don't regress this fix.

r=etienne
Bumping manifests a=b2g-bump