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

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https://hg.mozilla.org/integration/gaia-central/rev/b1cd6e86bc05
Author: Ed Morley <emorley@mozilla.com>
Desc: Revert "Bug 1037047 - fixed call options off screen transition screen reader visibility. r=drs" for gaia-ui-test failures

This reverts commit 7f3005a17c0c0cf015959224b80f6297120ff4aa.
Bumping manifests a=b2g-bump