Bumping gaia.json for 5 gaia revision(s) a=gaia-bump

Bumping gaia.json for 5 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_1/rev/7aeb23e68594
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Bug 1015853 - Changing theme should update wallpaper image r=arthurcc

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https://hg.mozilla.org/integration/gaia-2_1/rev/71d118530fbc
Author: Punam Dahiya <punamdahiya@yahoo.com>
Desc: Bug1082555-[Video]-Fix of currentVideo getting reset during suspend resume operation r=russn

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https://hg.mozilla.org/integration/gaia-2_1/rev/f2063ac41f36
Author: Alexandre Lissy <lissyx+github@lissyx.dyndns.org>
Desc: Bug 1083729 - Avoid callscreen window leakage r=etienne_s

Because of a platform bug, the callscreen window gets leaked in bfcache,
as documented on bug 1078448 and stated in comment 8. Adding an empty
'unload' event listener allows us to avoid the leakage.

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https://hg.mozilla.org/integration/gaia-2_1/rev/10414e733a5b
Author: Yura Zenevich <yzenevich@mozilla.com>
Desc: Bug 1081319 - fixing statusbar icons wrapper visibility in full screen app mode. r=mhenretty

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https://hg.mozilla.org/integration/gaia-2_1/rev/e5bfb189f886
Author: Guillaume Marty <edo999@gmail.com>
Desc: Bug 1069438 - [Status Bar] Play icon sometimes shows up when camera in use icon is shown