Bumping gaia.json for 4 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/4a99416d102f
Author: GaryChen(pychen) <mmm198219@gmail.com>
Desc: Merge pull request #14053 from dwi2/bug940188

Bug 940188 - Do checking before using IccHelper and mozMobileConnection r=crh0716

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https://hg.mozilla.org/integration/gaia-central/rev/2c946182b668
Author: tzhuang <tzhuang@mozilla.com>
Desc: Bug 940188 - Do checking before using IccHelper(mozIccManager) and mozMobileConnection

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https://hg.mozilla.org/integration/gaia-central/rev/36eebc74bf8c
Author: Askeing Yen (fyen) <askeing@gmail.com>
Desc: Merge pull request #14089 from zacc/bug_943598

Bug 943598 - Add explicit wait to Persona frame in UI tests to remove de...

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https://hg.mozilla.org/integration/gaia-central/rev/994bebda9cd9
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 943598 - Add explicit wait to Persona frame in UI tests to remove dependency on implicit wait