Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_4/rev/837f2a950af3
Author: gitmai <mri@tid.es>
Desc: Merge pull request #17474 from gitmai/bug-986473-CC-modify-parameters

Bug 986473 -Modify cost control parameters
r=salva
Bumping manifests a=b2g-bump