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

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https://hg.mozilla.org/integration/gaia-central/rev/5867d3a26830
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Merge pull request #18693 from wilsonpage/994077

Bug 994077 - [Camera][Hamachi] Long wait for initial preview stream

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https://hg.mozilla.org/integration/gaia-central/rev/cecebd9d0ff3
Author: Wilson Page <wilsonpage@me.com>
Desc: Bug 994077 - [Camera][Hamachi] Long wait for initial preview stream
Bumping manifests a=b2g-bump