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

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https://hg.mozilla.org/integration/gaia-central/rev/a22c634e2dda
Author: retornam <retornam@users.noreply.github.com>
Desc: Merge pull request #12272 from bobsilverberg/bug917276

Bug 917276 - Update lockscreen app and tests to address changes to the lockscreen markup

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https://hg.mozilla.org/integration/gaia-central/rev/16c313e6aaeb
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Address review comments.
Replaced calls to launch(), changed method name, made wait_for explicit.

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https://hg.mozilla.org/integration/gaia-central/rev/f123d13ce40e
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Bug 917276 - Update lockscreen app and tests to address changes to the lockscreen markup