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

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https://hg.mozilla.org/integration/gaia-central/rev/a865859744d4
Author: AndreiH <andrei.hutusoru@softvision.ro>
Desc: Merge pull request #15796 from chirarobert/unxfail

Re-enable test_persona_app.py on devices due to Bug 963582 being resolve...

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https://hg.mozilla.org/integration/gaia-central/rev/fead4832e217
Author: chirarobert <chirarobert@yahoo.com>
Desc: Re-enable test_persona_app.py on devices due to Bug 963582 being resolved.
Bumping manifests a=b2g-bump