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

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https://hg.mozilla.org/integration/gaia-2_0/rev/18c002c08be7
Author: Ryan VanderMeulen <ryanvm@gmail.com>
Desc: Merge pull request #23931 from cctuan/1059822-v20

Bug 1059822 - close simpindialog if lockscreen is unlocked to camera app

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https://hg.mozilla.org/integration/gaia-2_0/rev/2aa414c424e7
Author: cctuan <georgeiscoming@gmail.com>
Desc: Bug 1059822 - close simpindialog if lockscreen is unlocked to camera app
Bumping manifests a=b2g-bump