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

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https://hg.mozilla.org/integration/gaia-central/rev/a72c0b9dddb3
Author: Florin Strugariu <bebef_1987@yahoo.com>
Desc: Merge pull request #23408 from chirarobert/fix_settings_root

Bug 1059681 - [v2.1] Fix test_settings_root.py

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https://hg.mozilla.org/integration/gaia-central/rev/a987af69aab9
Author: Robert Chira <robertchira@P5075.(none)>
Desc: Bug 1059681 - [v2.1] Fix test_settings_root.py
Bumping manifests a=b2g-bump