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

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https://hg.mozilla.org/integration/gaia-central/rev/555f1a2b8526
Author: Fernando Rodríguez Sela <frsela@tid.es>
Desc: Merge pull request #13341 from frsela/STK/Bug932712

Bug 932712 - [STK] There is a grey line on top of the menu, r=kaze

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https://hg.mozilla.org/integration/gaia-central/rev/7e9020cd182f
Author: Fernando Rodriguez Sela <frsela@tid.es>
Desc: Bug 932712 - [STK] There is a grey line on top of the menu

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https://hg.mozilla.org/integration/gaia-central/rev/44ecb2d47e87
Author: Fabien Cazenave <fabien@cazenave.cc>
Desc: Merge pull request #13214 from soumyakanti/solution

Bug 931640 - Fix translation of Reset PIN2 Code across the locales, r=kaze

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https://hg.mozilla.org/integration/gaia-central/rev/740cfdf543e2
Author: Soumya Kanti Chakraborty <soumyakanti.chakraborty@gmail.com>
Desc: Bug 931640 - Fix translation of Reset PIN2 Code across the locales