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

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https://hg.mozilla.org/integration/gaia-central/rev/99d5a7c6f3b1
Author: Jose M. Cantera <jmcanterafonseca@gmail.com>
Desc: Merge pull request #20423 from jmcanterafonseca/multi_contacts

Bug 989927 - [Contacts][Refactor] Create a library that reads the Global...

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https://hg.mozilla.org/integration/gaia-central/rev/8850fdfd9215
Author: José Manuel Cantera <jmcanterafonseca@gmail.com>
Desc: Bug 989927 - [Contacts][Refactor] Create a library that reads the Global Contacts DataStore and provide a single contact
Bumping manifests a=b2g-bump