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

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https://hg.mozilla.org/integration/gaia-central/rev/3f894361c59b
Author: lissyx <lissyx+github@lissyx.dyndns.org>
Desc: Merge pull request #24693 from lissyx/bug1071235

Bug 1071235 - Fix touching fullscreen video displaying controls r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/5f4124678bdd
Author: Alexandre Lissy <lissyx+github@lissyx.dyndns.org>
Desc: Bug 1071235 - Fix touching fullscreen video displaying controls r=alive

CSS background-color in ".appWindow.collapsible .screenshot-overlay"
makes the platform breaking tapping on a fullscreen video. Setting
'visiblity: hidden' when we are fullscreen does workaround the issue.
Bumping manifests a=b2g-bump