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

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https://hg.mozilla.org/integration/gaia-central/rev/6cac64d632fe
Author: Florin Strugariu <florin.strugariu@softvision.ro>
Desc: Merge pull request #24565 from viorelaioia/bug_1074815

Bug 1074815 - Update tests as browser app was removed

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https://hg.mozilla.org/integration/gaia-central/rev/e20a577ccbfe
Author: Viorela Ioia <viorelaioia@gmail.com>
Desc: Bug 1074815 - Update tests as browser app was removed
Bumping manifests a=b2g-bump