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

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https://hg.mozilla.org/integration/gaia-central/rev/0927ccf3a87e
Author: Ed Morley <emorley@mozilla.com>
Desc: Revert "Bug 924833 - Re-enable test_receive_call.py" for requiring plivo, which isn't on the mirror

This reverts commit e582fc3be7030e0ce58e385b8951491f64913254.
Bumping manifests a=b2g-bump