Bumping gaia.json for 2 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/d4655ff5c2fc
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Merge pull request #12167 from dmarcos/master

Bug 914998 - [Gallery] Edit Mode - Replacing buttons text labels with icons

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https://hg.mozilla.org/integration/gaia-central/rev/dad52e685c90
Author: Diego Marcos <diego.marcos@gmail.com>
Desc: Bug 914998 - [Gallery] Edit Mode - Replacing buttons text labels with icons