Bumping gaia.json for 3 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/4c0269f672ec
Author: Florin Strugariu <bebef_1987@yahoo.com>
Desc: Merge pull request #12586 from zacc/bug-922686

Bug 922686 - update lockscreen locator r=bebef1987

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https://hg.mozilla.org/integration/gaia-central/rev/a837d3ccc1a5
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 922686 - update lockscreen locator r=bebef1987

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https://hg.mozilla.org/integration/gaia-central/rev/350ad8445a09
Author: Yannick Assogba <yassogba@gmail.com>
Desc: Bug 919567 - Stopwatch and Timer Panels do not update from underlying data objects

r=jugglinmike