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

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https://hg.mozilla.org/integration/gaia-central/rev/6e46ea20f097
Author: Miller Medeiros <miller@millermedeiros.com>
Desc: Merge pull request #21508 from millermedeiros/1002904-shared-icon-font

Bug 1002904 - calendar cold launch regression 100ms hamachi Apr23-Apr25 r=gaye

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https://hg.mozilla.org/integration/gaia-central/rev/487a7508e80c
Author: Miller Medeiros <miller@millermedeiros.com>
Desc: Bug 1002904 - calendar cold launch regression 100ms hamachi Apr23-Apr25
Bumping manifests a=b2g-bump