Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_1/rev/6557288a0af6
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #23655 from timdream/keyboard-rocketbar-miss

Bug 1061439 - Stop JS error by preventing IMEngine from interact with Glue, r=rudyl
Conflicts:
	apps/keyboard/index.html

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https://hg.mozilla.org/integration/gaia-2_1/rev/cf954ebde361
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #23602 from crh0716/1061391

Bug 1061391 - Remove the button of clear browsing data r=eragonj

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https://hg.mozilla.org/integration/gaia-2_1/rev/771ef5a4f7b5
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #23609 from crh0716/1061042

Bug 1061042 - Add the icon for EU roaming r=alive
Bumping manifests a=b2g-bump