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

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https://hg.mozilla.org/integration/gaia-central/rev/f3c5538b8d7c
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Merge pull request #14109 from Rik/two-calls-correction-923059

Bug 923059 - Call screen layout corrections r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/63579015a87e
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Bug 923059 - Call screen layout corrections