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

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https://hg.mozilla.org/integration/gaia-central/rev/27357877d17b
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #18464 from KevinGrandon/bug_996968_homescreen_bookmark_tests

Bug 996968 - Intermittent gaia-integration TEST-UNEXPECTED-FAIL | Update bookmark on homescreen > Navigate to sample.html and bookmark it on homescreen

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https://hg.mozilla.org/integration/gaia-central/rev/e3c60336bef0
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 996968 - Intermittent gaia-integration TEST-UNEXPECTED-FAIL | Update bookmark on homescreen > Navigate to sample.html and bookmark it on homescreen r=dwi2
Bumping manifests a=b2g-bump