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

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https://hg.mozilla.org/integration/gaia-central/rev/8e6c3e82c808
Author: Rudy Lu <me@rudy.lu>
Desc: Merge pull request #26476 from RudyLu/keyboard/Bug1091018-altMenu_for_secondLayout

Bug 1091018 - [flatfish][Ar][TCP][keyboard] missing letters.
r=timdream.

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https://hg.mozilla.org/integration/gaia-central/rev/28196b30eda5
Author: Rudy Lu <me@rudy.lu>
Desc: Bug 1091018 - [flatfish][Ar][TCP][keyboard] missing letters.
 - Don't hide key label in the alternative char menu.
Bumping manifests a=b2g-bump