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

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https://hg.mozilla.org/integration/gaia-central/rev/18965116480b
Author: Askeing Yen (fyen) <askeing@gmail.com>
Desc: Merge pull request #14136 from zacc/bug_943996

Bug 943996 - Improve wait after tapping update in contacts edit r=Askein...

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https://hg.mozilla.org/integration/gaia-central/rev/a62462928629
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 943996 - Improve wait after tapping update in contacts edit r=Askeing