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

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https://hg.mozilla.org/integration/gaia-central/rev/c240685cbba3
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #21274 from chirarobert/move_app_fix_master

Bug 1033346 - [v2.0] Fix test_homescreen_move_app.py failure

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https://hg.mozilla.org/integration/gaia-central/rev/907d4580146b
Author: chirarobert <robert.chira@softvision.ro>
Desc: Bug 1033346 - [v2.0] Fix test_homescreen_move_app.py failure
Bumping manifests a=b2g-bump