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

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https://hg.mozilla.org/integration/gaia-central/rev/b942f84f82d2
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #26497 from davidflanagan/bug1059682

Bug 1059682: properly relocalize thumbnail dates and sizes r=pdahiya

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https://hg.mozilla.org/integration/gaia-central/rev/793a51475e7f
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Bug 1059682: properly relocalize thumbnail dates and sizes

fix unit tests
Bumping manifests a=b2g-bump