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

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https://hg.mozilla.org/integration/gaia-central/rev/6792a68929d3
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #25831 from alivedise/bugzilla/1084495_master/commit-close

Bug 1084495 - Commit close in kill, r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/2acc4f665843
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 1084495 - Commit close in kill
Bumping manifests a=b2g-bump