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

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https://hg.mozilla.org/integration/gaia-central/rev/ab822e8ed326
Author: Corey Frang <gnarf37@gmail.com>
Desc: Bug 936643 - [Settings] Implement ListView.destroy() - r=arthurcc

- Adds `Observable().unobserve` as well as `ObservableArray.unobserve()`
- Adds `ListView().destroy()`
- Adds an element cache for `ListView` so that a re-used element can automatically destroy it's old `ListView`

Closes gh-13724