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

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https://hg.mozilla.org/integration/gaia-central/rev/441f0eb16eeb
Author: Ian Liu <iliu@mozilla.com>
Desc: Merge pull request #17788 from ian-liu/system2/bug964653_system_dialog_refactor_

Bug 964653 - (system-dialog) [Window Management] Implement System Dialog Window, r=@alivedise

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https://hg.mozilla.org/integration/gaia-central/rev/ea0eb5d6f5c1
Author: ian-liu <iliu@mozilla.com>
Desc: Bug 964653 - (system-dialog) [Window Management] Implement System Dialog Window
Bumping manifests a=b2g-bump