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

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https://hg.mozilla.org/integration/gaia-central/rev/225becbfeb68
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Merge pull request #17706 from dmarcos/bug948263

Bug948263

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https://hg.mozilla.org/integration/gaia-central/rev/50534bee9dfd
Author: ashish.singh <ashish.singh@lge.com>
Desc: Bug 948263 - [User Story] Warning when the battery is low while recording a video
Bumping manifests a=b2g-bump