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

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https://hg.mozilla.org/integration/gaia-central/rev/5591190e1b7c
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #23134 from yurenju/media-resolution-file-remove

Bug 1053711 - call nsIFile.remove() only if it exists in build/media-resolution.js r=gduan

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https://hg.mozilla.org/integration/gaia-central/rev/8d24ef87bf46
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1053711 - call nsIFile.remove() only if it exists in build/media-resolution.js r=gduan
Bumping manifests a=b2g-bump