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

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https://hg.mozilla.org/integration/gaia-central/rev/1f74ed6d8d91
Author: John Hu <johu@mozilla.com>
Desc: Merge pull request #16017 from vsireesha246/Bug_922609_Dispatching_Video_Scan_End_Event

[Video]Bug_922609_Provide a way for tests to determine that the video app has f... r=johnhu

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https://hg.mozilla.org/integration/gaia-central/rev/fc9bd0603043
Author: varada.sireesha <varada.sireesha@lge.com>
Desc: Bug_922609_Provide a way for tests to determine that the video app has finished scanning
Bumping manifests a=b2g-bump