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

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https://hg.mozilla.org/integration/gaia-central/rev/89e8095a1515
Author: Wilson Page <wilsonpage@me.com>
Desc: Merge pull request #18858 from wilsonpage/1004420

Bug 1004420 - Spinner over camera preview

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https://hg.mozilla.org/integration/gaia-central/rev/df0b0a93468b
Author: Wilson Page <wilsonpage@me.com>
Desc: Bug 1004420 - Spinner over camera preview
Bumping manifests a=b2g-bump