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

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https://hg.mozilla.org/integration/gaia-central/rev/7a53aa54b708
Author: Arnau <arnau@arnaumarch.com>
Desc: Merge pull request #14482 from rnowm/hihglight-call-log

Bug 917820 - [Call Log] Use Full Line Highlights

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https://hg.mozilla.org/integration/gaia-central/rev/22a0d15b9eab
Author: rnowm <arnau@arnaumarch.com>
Desc: Bug 917820 - [Call Log] Use Full Line Highlights