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

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https://hg.mozilla.org/integration/gaia-central/rev/cb7228e13dd0
Author: Rex KM Lee <rexboy@mozilla.com>
Desc: Merge pull request #14523 from rexboy7/fix-bug917221

Bug 917221 - [Dialer] Support merging group call by Bluetooth CHLD=3 com... r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/45b3a22c1903
Author: Rex Lee <rexboy@mozilla.com>
Desc: Bug 917221 - [Dialer] Support merging group call by Bluetooth CHLD=3 command.