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

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https://hg.mozilla.org/integration/gaia-central/rev/bc4ef2ddcacf
Author: BavarianTomcat <tomcat@mozilla.com>
Desc: Revert "Bug 1009099 - Remove wait_for_* methods from GaiaTestCase where possible" for permanent test failures

This reverts commit 2a022144eda620001c9fbdad1faae3a5f60e8e30.
Bumping manifests a=b2g-bump