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

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https://hg.mozilla.org/integration/gaia-central/rev/f4763519da1d
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #15525 from etiennesegonzac/bug-961635-lockscreen-alt-camera-click

Bug 961635 - Listen to click instead of touchstart on the lockscreen (with code) camera button r=gweng

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https://hg.mozilla.org/integration/gaia-central/rev/ec030d91fdad
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 961635 - Listen to click instead of touchstart on the lockscreen (with code) camera button to prevent accidental launch of the camera.
Bumping manifests a=b2g-bump