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

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https://hg.mozilla.org/integration/gaia-central/rev/099067b239b1
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #20673 from yurenju/fs-error

Bug 1026988 - Better error handling for file accessing in build system r=@cctuan

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https://hg.mozilla.org/integration/gaia-central/rev/c74ed9b268b0
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1026988 - Better error handling for file accessing in build system
Bumping manifests a=b2g-bump