Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/3769422ffec7
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 996683 - Disable intermittent failing test, Find My Device lock > Lock the screen through the test app

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https://hg.mozilla.org/integration/gaia-central/rev/42cb9682e265
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Merge pull request #18297 from kumarrishav/issue-980395

Bug 980395 - Remove navigator.mozMobileConnection uses from the FTU app r=fcampo

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https://hg.mozilla.org/integration/gaia-central/rev/89a203cf0849
Author: kumarrishav <rishav006@gmail.com>
Desc: Bug 980395 - Remove navigator.mozMobileConnection uses from the FTU app
Bumping manifests a=b2g-bump