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

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https://hg.mozilla.org/integration/gaia-central/rev/3f6148d60ac7
Author: Germán Toro del Valle <gtorodelvalle@gmail.com>
Desc: Merge pull request #15155 from gtorodelvalle/contacts-bug-958012

Bug 958012 - [Contacts] search.js not dealing with the correct navigationStack instance

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https://hg.mozilla.org/integration/gaia-central/rev/46ce4ea256bf
Author: Germán Toro del Valle <gtorodelvalle@gmail.com>
Desc: Bug 958012 - [Contacts] search.js not dealing with the correct navigationStack instance