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

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https://hg.mozilla.org/integration/gaia-central/rev/2d53c8213843
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #16928 from KevinGrandon/bug_971564_system_telephony_settings_v2

Bug 971564 - [System2] TelephonySettings updates r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/c3d088d71c59
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 971564 - [System2] TelephonySettings updates r=alive
Bumping manifests a=b2g-bump