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

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https://hg.mozilla.org/integration/gaia-central/rev/17b27134fb2a
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #25120 from crh0716/1082234

Bug 1082234 - Set a default value when the stored value is unavailable r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/2e9ce4bd3375
Author: Arthur Chen <crh0716@gmail.com>
Desc: Bug 1082234 - Set a default value when the stored value is unavailable
Bumping manifests a=b2g-bump