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

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https://hg.mozilla.org/integration/gaia-central/rev/417937307d7d
Author: vingtetun <21@vingtetun.org>
Desc: Merge pull request #16432 from heycam/typo

Bug 974228 - Fix typo in name of Icon.savePosition.

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https://hg.mozilla.org/integration/gaia-central/rev/279fc0bbf08d
Author: Cameron McCormack <cam@mcc.id.au>
Desc: Bug 974228 - Fix typo in name of Icon.savePosition. r=21
Bumping manifests a=b2g-bump