Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/319c1284148e
Author: Wilson Page <wilsonpage@me.com>
Desc: Merge pull request #25029 from wilsonpage/1081126

Bug 1081126 - [gaia-theme] Sub-themes need to be more specific for nesting to

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https://hg.mozilla.org/integration/gaia-central/rev/b84998b2a23a
Author: Wilson Page <wilsonpage@me.com>
Desc: Bug 1081126 - [gaia-theme] Sub-themes need to be more specific for nesting to work
Bumping manifests a=b2g-bump