Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/d0f0289f0c27
Author: Ryan VanderMeulen <ryanvm@gmail.com>
Desc: Reset Gaia master to state prior to horkage.

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https://hg.mozilla.org/integration/gaia-central/rev/889cace84877
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #16553 from huchengtw-moz/system/Bug_971554_instantiable_soundmanager

Bug 971554 - [System2] Instantiable SoundManager, r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/7c79b44ebb90
Author: John Hu <johu@mozilla.com>
Desc: Bug 971554 - [System2] Instantiable SoundManager
Bumping manifests a=b2g-bump