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

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https://hg.mozilla.org/integration/gaia-central/rev/0b0977000fca
Author: Gregor Wagner <anygregor@gmail.com>
Desc: Merge pull request #12340 from JonHylands/jhylands-867320-calendar-reference-workloads-master

Bug 867320 - Calendar reference workloads

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https://hg.mozilla.org/integration/gaia-central/rev/6c00ecfa5fa3
Author: Jon Hylands <jhylands@mozilla.com>
Desc: Bug 867320 - Calendar reference workloads