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

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https://hg.mozilla.org/integration/gaia-central/rev/5228b1619ad1
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #19016 from KevinGrandon/bug_1006997_bootstrap_test_generate_mocks

Bug 1006997 - Use real files in bootstrap_test.js

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https://hg.mozilla.org/integration/gaia-central/rev/8ee0617d88f4
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1006997 - Use real files in bootstrap_test.js r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/1ec77fed13f2
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #19122 from KevinGrandon/bug_985460_home2_drag_drop_delay

Bug 985460 - [Home2] Follow-up, remove additional contextmenu delay

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https://hg.mozilla.org/integration/gaia-central/rev/1685e0659e8a
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 985460 - [Home2] Follow-up, remove additional contextmenu delay r=me
Bumping manifests a=b2g-bump