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

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https://hg.mozilla.org/integration/gaia-central/rev/b56a12c913cb
Author: Greg Weng <snowmantw@gmail.com>
Desc: Merge pull request #24763 from snowmantw/issue1054904

Bug 1054904 - Do not wait for foreground app to paint before starting un...

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https://hg.mozilla.org/integration/gaia-central/rev/bcd473bfb337
Author: Greg Weng <snowmantw@gmail.com>
Desc: Bug 1054904 - Do not wait for foreground app to paint before starting unlock
Bumping manifests a=b2g-bump