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

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https://hg.mozilla.org/integration/gaia-central/rev/973662e5df41
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #16469 from KevinGrandon/bug_952611_disable_failing_tests

Bug 952611 - Disable intermittent tests

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https://hg.mozilla.org/integration/gaia-central/rev/c2cb134d242b
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 952611 - Disable intermittent tests
Bumping manifests a=b2g-bump