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

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https://hg.mozilla.org/integration/gaia-central/rev/697763c3e05d
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #17720 from KevinGrandon/bug_864178_test_agent_sandboxing

Bug 864178 - [TestAgent] Run each test in its own sandbox

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https://hg.mozilla.org/integration/gaia-central/rev/54ee88cd4c62
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 864178 - [TestAgent] Run each test in its own sandbox r=julienw
Bumping manifests a=b2g-bump