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

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https://hg.mozilla.org/integration/gaia-central/rev/212b12ea7f81
Author: Albert <acperez@tid.es>
Desc: Merge pull request #16616 from acperez/bug-973611

Bug 973611 - Configure keyboard settings through single-variant. r=yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/6cc5b2de6bf5
Author: Albert <acperez@tid.es>
Desc: Bug 973611 - Configure keyboard settings through single-variant. r=yurenju
Bumping manifests a=b2g-bump