Bumping gaia.json for 4 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/ebe053f5cad8
Author: Jim Porter <squibblyflabbetydoo@gmail.com>
Desc: Merge pull request #11138 from mozsquib/email-activesync-fix-user-param

Bug 897308 - [email/activesync] Username in URL query is "undefined"

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https://hg.mozilla.org/integration/gaia-central/rev/2b326bb70272
Author: Jim Porter <jporter@mozilla.com>
Desc: Bug 897308 - [email/activesync] Username in URL query is "undefined"; r=asuth

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https://hg.mozilla.org/integration/gaia-central/rev/651a53c98e3f
Author: Rex KM Lee <rexboy@mozilla.com>
Desc: Merge pull request #11005 from rexboy7/fix-bug890869-master

Bug 890869 - [FM] @1.5x asset revise

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https://hg.mozilla.org/integration/gaia-central/rev/e52efc53112b
Author: Rex Lee <rexboy@mozilla.com>
Desc: Bug 890869 - [FM] @1.5x asset revise