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

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https://hg.mozilla.org/integration/gaia-central/rev/5a2bd8b7aa5d
Author: Yura Zenevich <yura.zenevich@gmail.com>
Desc: Merge pull request #23873 from yzen/bug-1045017

Bug 1045017 - fixing screen reader status bar accessibility. Statusbar i...

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https://hg.mozilla.org/integration/gaia-central/rev/5abf8540f6a3
Author: Yura Zenevich <yzenevich@mozilla.com>
Desc: Bug 1045017 - fixing screen reader status bar accessibility. Statusbar improvements during app transitions.
Bumping manifests a=b2g-bump