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

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https://hg.mozilla.org/integration/gaia-central/rev/39030314e8dd
Author: Zac <zcampbell@mozilla.com>
Desc: Revert "Bug 1039966 - Update gaiatest marionette_client to 0.8.1 and dependency moztest to >= 0.6"

This reverts commit 6a689063ea6b8f10b7b9476ccca94af6f1dc803f.

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https://hg.mozilla.org/integration/gaia-central/rev/5f98fe0e72df
Author: Min-Zhong "John" Lu <mnjul@users.noreply.github.com>
Desc: Merge pull request #22136 from mnjul/bug_1043121_imeswitcher_to_another_script_again

Bug 1043121 - Move IMESwitcher in keyboard_manager to another script. r=timdream

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https://hg.mozilla.org/integration/gaia-central/rev/2a5f5ee2a26f
Author: John Lu [:mnjul] <jlu@mozilla.com>
Desc: Bug 1043121 - Move IMESwitcher in keyboard_manager to another script
Bumping manifests a=b2g-bump