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

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https://hg.mozilla.org/integration/gaia-central/rev/a43f6c119d80
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Merge pull request #15565 from mikehenrty/disable_notification_get_tbpl

Bug 960126 - disable intermittent test

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https://hg.mozilla.org/integration/gaia-central/rev/74f0915f1f17
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Bug 960126 - disable intermittent test
Bumping manifests a=b2g-bump