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

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https://hg.mozilla.org/integration/gaia-central/rev/4c362fcebca8
Author: RickyChien <ricky060709@gmail.com>
Desc: Merge pull request #24276 from RickyChien/bug-963009

Bug 963009 - [Gaia][Build] Test coverage r=@yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/5d228139d199
Author: cctuan <georgeiscoming@gmail.com>
Desc: Bug 963009 - [Gaia][Build] Test coverage
Bumping manifests a=b2g-bump