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

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https://hg.mozilla.org/integration/gaia-central/rev/a3a27b796944
Author: Florin Strugariu <bebef_1987@yahoo.com>
Desc: Merge pull request #15204 from AlinT/bug_958545

Bug 958545 - Update call screen locartor changed in Bug 952099

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https://hg.mozilla.org/integration/gaia-central/rev/529608001052
Author: AlinT <trifandreialin@gmail.com>
Desc: Bug 958545 - Update call screen locartor changed in Bug 952099