Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/d2b5155abc89
Author: KWierso <kwierso@gmail.com>
Desc: Revert "Merge pull request #20501 from sfoster/bug-1023179-tutorial-tests" for Gaia-ui test failures

This reverts commit 82cccd171556baa330a2ae26aaf994987aee19c2, reversing
changes made to bd5888a2c883712d07a058e4600bfa04b8b19af4.
Bumping manifests a=b2g-bump