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

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https://hg.mozilla.org/integration/gaia-central/rev/8c6af64b6c03
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #19008 from KevinGrandon/bug_841422_template_test_to_sharedtest

Bug 841422 - Follow-up, move template_test.js into sharedtest

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https://hg.mozilla.org/integration/gaia-central/rev/a4f31dc26227
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 841422 - Follow-up, move template_test.js into sharedtest r=me
Bumping manifests a=b2g-bump