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

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https://hg.mozilla.org/integration/gaia-2_0/rev/858d4bb81508
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Revert "Merge pull request #21118 from gmarty/Bug-1027391-SIM-lock-shows-transparent-status-bar"

This reverts commit 16410831c2e513b5cabc550363f28a023dc256be.
Bumping manifests a=b2g-bump