Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/1251739ff9aa
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #19766 from zacc/case-10687

Case 10687

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https://hg.mozilla.org/integration/gaia-central/rev/3af285912edd
Author: Zac <zcampbell@mozilla.com>
Desc: Bug 993236 - Update test_settings_dsds_cell_data as per review comments

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https://hg.mozilla.org/integration/gaia-central/rev/9b9c5bbec813
Author: alison-shiue <alison@alison-u-pc.(none)>
Desc: Bug 993236 - [dsds] Access Cellular & Data setting (Two SIM inserted)
Bumping manifests a=b2g-bump