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

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https://hg.mozilla.org/integration/gaia-central/rev/c7681561e44b
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Merge pull request #16345 from asutherland/email-contenteditable

Bug 837251 - Compose textarea doesn't occupy available screen space or show bounding box. r=asuth

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https://hg.mozilla.org/integration/gaia-central/rev/20f5cd588393
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 837251 - Compose textarea doesn't occupy available screen space or show bounding box. r=asuth

Includes some minor review fixes by asuth.
Bumping manifests a=b2g-bump