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

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https://hg.mozilla.org/integration/gaia-1_3/rev/79743c5a34b3
Author: Ben Tian <btian@mozilla.com>
Desc: Merge pull request #16642 from bentian/bug-972142

Bug 972142 - Set camera preview style with CSS pixel, r=djf, a=1.3+

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https://hg.mozilla.org/integration/gaia-1_3/rev/6aa5cede2a89
Author: Ben Tian <btian@mozilla.com>
Desc: Bug 972142 - Set camera preview style with CSS pixel, r=djf, a=1.3+
Bumping manifests a=b2g-bump