Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/e2fad48ac3a6
Author: Eitan Isaacson <eitan@monotonous.org>
Desc: Merge pull request #18957 from eeejay/bug-895443

Bug 895443 - Add labels to necessary keyboard buttons and give pressed s... r=rlu

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https://hg.mozilla.org/integration/gaia-central/rev/41d26bcd79fb
Author: Eitan Isaacson <eitan@monotonous.org>
Desc: Bug 895443 - Add labels to necessary keyboard buttons and give pressed state to shift key.

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https://hg.mozilla.org/integration/gaia-central/rev/89446da23a27
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 985459 - Follow-up, address icon height size r=me

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https://hg.mozilla.org/integration/gaia-central/rev/a6f6c1f22042
Author: crdlc <crdlc@tid.es>
Desc: Bug 985459 - [User Story] Icon Scaling based on Grid Configuration and Screen Characteristics r=kgrandon
Bumping manifests a=b2g-bump