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

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https://hg.mozilla.org/integration/gaia-central/rev/da9e9c8e29a5
Author: Marshall Culpepper <marshall.law@gmail.com>
Desc: Merge pull request #25043 from marshall/bug1071451_incomingCall

Bug 1071451: [AUM] Handle attention windows properly so calls are counted

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https://hg.mozilla.org/integration/gaia-central/rev/20f2b69600f9
Author: Marshall Culpepper <marshall@mozilla.com>
Desc: Bug 1071451: [AUM] Handle attention windows properly so phone calls are counted. r=djf
Bumping manifests a=b2g-bump