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

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https://hg.mozilla.org/integration/gaia-central/rev/88155b68ab14
Author: GaryChen(pychen) <mmm198219@gmail.com>
Desc: Merge pull request #12792 from luke-chang/925685_test_keyboard_app_height

Bug 925685 - Make test keyboard app change its window height correctly. r=timdream.

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https://hg.mozilla.org/integration/gaia-central/rev/bf4f3dcec39e
Author: Luke Chang <lchang@mozilla.com>
Desc: Bug 925685 - Make test keyboard app change its window height correctly, r=timdream