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

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https://hg.mozilla.org/integration/gaia-central/rev/1b1b21f51115
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Merge pull request #21488 from shufang-xu/bug1033889xsf_master

 Bug 1033889 - unable to read cell broadcast message on lock screen. r=ferjmoreno,Michael Henretty

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https://hg.mozilla.org/integration/gaia-central/rev/1862a1f9beb7
Author: arvin zhang <arvin.zhang@spreadtrum.com>
Desc: Bug 1033889 - unable to read cell broadcast message on lock screen. r=ferjmoreno,Michael Henretty
Bumping manifests a=b2g-bump