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

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https://hg.mozilla.org/integration/gaia-central/rev/fc672657f542
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Merge pull request #19091 from dominickuo/bug-998100

Bug 998100 - [Settings] add new localized string for dial pad, r=EragonJ

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https://hg.mozilla.org/integration/gaia-central/rev/a5727bc2a198
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Bug 998100 - [Settings] add new localized string for dial pad
Bumping manifests a=b2g-bump