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

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https://hg.mozilla.org/integration/gaia-central/rev/3c6721504d29
Author: Min-Zhong "John" Lu <mnjul@users.noreply.github.com>
Desc: Merge pull request #21254 from mnjul/1031505_switch_keyboard_caps

Bug 1031505 - Switching keyboard layout type when messaging enables capslocks. r=timdream

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https://hg.mozilla.org/integration/gaia-central/rev/4027f46d45f2
Author: John Lu [:mnjul] <jlu@mozilla.com>
Desc: Bug 1031505 - Switching keyboard layout type when messaging enables capslocks
Bumping manifests a=b2g-bump