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

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https://hg.mozilla.org/integration/gaia-central/rev/ae9107ab7578
Author: Hubert Figuière <hub@figuiere.net>
Desc: Merge pull request #19840 from eliperelman/bug-1015405-settings-implement-new-perf-events

Bug 1015405 - Fixing incorrect naming of visually complete event r=hub,arthur.chen

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https://hg.mozilla.org/integration/gaia-central/rev/857737ba54ec
Author: Eli Perelman <eli@eliperelman.com>
Desc: Bug 1015405 - Fixing incorrect naming of visually complete event
Bumping manifests a=b2g-bump