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

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https://hg.mozilla.org/integration/gaia-central/rev/e20fbec44769
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #19200 from zacc/bug_1005272

Bug 1005272 - Attempt resolve intermittent failure in test_settings_chan...

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https://hg.mozilla.org/integration/gaia-central/rev/5ab470957a99
Author: Zac <zcampbell@mozilla.com>
Desc: Bug 1005272 - Re-enabled test_settings_change_keyboard_language.py
Bumping manifests a=b2g-bump