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

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https://hg.mozilla.org/integration/gaia-central/rev/3b348ad0a7f6
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #18831 from viorelaioia/bug_1003746

Bug 1003746 - Fix the tap_subject() method of email apps

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https://hg.mozilla.org/integration/gaia-central/rev/84513fe4ef27
Author: Viorela Ioia <viorelaioia@gmail.com>
Desc: Bug 1003746 - Fix the tap_subject() method of email apps

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https://hg.mozilla.org/integration/gaia-central/rev/5bb6f4292658
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #18843 from bobsilverberg/bug1004138

Bug 1004138 - Add a step to cleanup_data to eliminate remembered networks

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https://hg.mozilla.org/integration/gaia-central/rev/773368b4d521
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Bug 1004138 - Add a step to cleanup_data to eliminate remembered networks
Bumping manifests a=b2g-bump