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

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https://hg.mozilla.org/integration/gaia-central/rev/2304824ac517
Author: Yoshi Huang <allstars.chh@mozilla.com>
Desc: Merge pull request #19293 from kamituel/Bug_1005896_pairing_ui_tests

Bug 1005896: Pairing UI unit tests. r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/dafee6165507
Author: Kamil Leszczuk <kamituel@gmail.com>
Desc: Bug 1005896: Pairing UI unit tests.
Bumping manifests a=b2g-bump