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

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https://hg.mozilla.org/integration/gaia-central/rev/4fb5bfaab975
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #12712 from crdlc/bug-924120

Bug 924120 - Create a new test to check the new feature about copying ap...

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https://hg.mozilla.org/integration/gaia-central/rev/32920978706d
Author: crdlc <crdlc@tid.es>
Desc: Bug 924120 - Create a new test to check the new feature about copying apps into collections