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

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https://hg.mozilla.org/integration/gaia-central/rev/9ada9e6a6c2e
Author: vingtetun <21@vingtetun.org>
Desc: Merge pull request #16782 from vingtetun/bug978632

Bug 978632 - Prevent a click to fire when the home button is pressed on ...

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https://hg.mozilla.org/integration/gaia-central/rev/9a38bcdb6891
Author: Vivien Nicolas <21@vingtetun.org>
Desc: Bug 978632 - Prevent a click to fire when the home button is pressed on some devices. r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/58369bc13102
Author: vingtetun <21@vingtetun.org>
Desc: Merge pull request #16784 from vingtetun/bug978569

Bug 978569 - Can not use APP=homescreen anymore. r=crdlc

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https://hg.mozilla.org/integration/gaia-central/rev/8f3b15bea0fe
Author: Vivien Nicolas <21@vingtetun.org>
Desc: Bug 978569 - Can not use APP=homescreen anymore. r=crdlc
Bumping manifests a=b2g-bump