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

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https://hg.mozilla.org/integration/gaia-central/rev/a855a05df236
Author: Salvador de la Puente González <salva@unoyunodiez.com>
Desc: Merge pull request #14633 from gitmai/bug-948798-CC-reset-wifi-not-refresh

Bug 948798 - [Cost Control] After reset Wifi usage, the usage does not b...
r=me

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https://hg.mozilla.org/integration/gaia-central/rev/671846122766
Author: mai <mri@tid.es>
Desc: Bug 948798 - [Cost Control] After reset Wifi usage, the usage does not be reset