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

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https://hg.mozilla.org/integration/gaia-central/rev/53fb62ed7962
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #16635 from fabi1cazenave/smsTagBarWidth-bug974046

Bug 974046 - [Messages] Carrier tag bar width. r=schung, a=v1.4+

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https://hg.mozilla.org/integration/gaia-central/rev/5425d956db88
Author: Fabien Cazenave <fabien@cazenave.cc>
Desc: Bug 974046 - [Messages] Carrier tag bar width
Bumping manifests a=b2g-bump