Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_0/rev/49b5bccf7a88
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #22319 from nullaus/v2.0

Merge pull request #22229 from nullaus/bug1039631

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https://hg.mozilla.org/integration/gaia-2_0/rev/48ad7746210a
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #22229 from nullaus/bug1039631

bug 1039631 - Remove gradients from shared components and lockscreen.
(cherry picked from commit 80d9343cdce468eee9642829e68acc9ee0e47487)
Bumping manifests a=b2g-bump