Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/9b417201f8da
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #18757 from zacc/bug_1002494

Bug 1002494 - Split yocto from gaiatest out into separate file r=rwood

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https://hg.mozilla.org/integration/gaia-central/rev/96821f50f74d
Author: Zac <zcampbell@mozilla.com>
Desc: Bug 1002494 - Split yocto from gaiatest out into separate file r=rwood

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https://hg.mozilla.org/integration/gaia-central/rev/995320c7799f
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #17651 from airpingu/bug-915884-IAC-tests-part-4

Bug 915884 - Add tests for Inter-App Communication API (part 4, Gaia UI Marionette tests for APIs)

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https://hg.mozilla.org/integration/gaia-central/rev/86103a006532
Author: Gene Lian <airpingu@gmail.com>
Desc: Bug 915884 - Add tests for Inter-App Communication API (part 4, Gaia UI Marionette tests for APIs). r=squib r=ferjm
Bumping manifests a=b2g-bump