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

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https://hg.mozilla.org/integration/gaia-central/rev/ca178877d09f
Author: Yura Zenevich <yura.zenevich@gmail.com>
Desc: Merge pull request #26198 from yzen/bug-1069214

Bug 1069214 - added accessibility improvements for day/week view.

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https://hg.mozilla.org/integration/gaia-central/rev/958d59c4c8e5
Author: Yura Zenevich <yzenevich@mozilla.com>
Desc: Bug 1069214 - added accessibility improvements for day/week view.
Bumping manifests a=b2g-bump