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

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https://hg.mozilla.org/integration/gaia-central/rev/8efaa9a88a23
Author: evanxd <itoyxd@gmail.com>
Desc: Merge pull request #22716 from evanxd/bug-977050

Bug 977050 - Automate changing end date/time in Calendar r=millermedeiros

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https://hg.mozilla.org/integration/gaia-central/rev/f31a9549b415
Author: Evan Xd <itoyxd@gmail.com>
Desc: Bug 977050 - Automate changing end date/time in Calendar r=millermedeiros
Bumping manifests a=b2g-bump