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

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https://hg.mozilla.org/integration/gaia-2_0/rev/a7662d77830c
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #21494 from guilherme-pg/bug1030448-v2.0

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

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https://hg.mozilla.org/integration/gaia-2_0/rev/076f45c5e58d
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