Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/e301b0a2bbe2
Author: Hubert Figuière <hub@figuiere.net>
Desc: Merge pull request #22071 from hfiguiere/bug1042648

Overfill test fixes. r=eli

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https://hg.mozilla.org/integration/gaia-central/rev/1be9d62e6ad9
Author: Hubert Figuière <hub@figuiere.net>
Desc: Bug 981009 - Ensure the number overfill results match the number of runs.

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https://hg.mozilla.org/integration/gaia-central/rev/9bbb7ab3ead8
Author: Hubert Figuière <hub@figuiere.net>
Desc: Bug 1042648 - use the new event in the overfill test.
Bumping manifests a=b2g-bump