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

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https://hg.mozilla.org/integration/gaia-central/rev/7208f8d87131
Author: Carsten Book <tomcat@mozilla.com>
Desc: Merge pull request #21306 from kamituel/Bug_1000839_encodeNDEF_fix

Bug 1000839: Fixes and unit tests for NfcUtils.encodeNDEF(). r=snowmantw

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https://hg.mozilla.org/integration/gaia-central/rev/922949dc3a92
Author: Kamil Leszczuk <kamituel@gmail.com>
Desc: Bug 1000839: Fixes and unit tests for NfcUtils.encodeNDEF()

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https://hg.mozilla.org/integration/gaia-central/rev/03e96d8cc929
Author: Carsten Book <tomcat@mozilla.com>
Desc: Merge pull request #21247 from guilherme-pg/bug1030448-bad-lockscreen

Bug 1030448 - Also make the default lockscreen react to the 'lockscreen..... r=gweng

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https://hg.mozilla.org/integration/gaia-central/rev/3769cbf28688
Author: Guilherme Goncalves <guilherme.p.gonc@gmail.com>
Desc: Bug 1030448 - Also make the default lockscreen react to the 'lockscreen.lock-immediately' setting.
Bumping manifests a=b2g-bump