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

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https://hg.mozilla.org/integration/gaia-central/rev/19f84d481f82
Author: Greg Weng <snowmantw@gmail.com>
Desc: Merge pull request #24822 from snowmantw/bug1078221

Bug 1078221 - [LockScreen][FTU] LockScreen would overlap on FTU app

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https://hg.mozilla.org/integration/gaia-central/rev/cc067a6cfef0
Author: Greg Weng <snowmantw@gmail.com>
Desc: Bug 1078221 - [LockScreen][FTU] LockScreen would overlap on FTU app
Bumping manifests a=b2g-bump