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

========

https://hg.mozilla.org/integration/gaia-central/rev/d8813553b3ec
Author: Min-Zhong "John" Lu <mnjul@users.noreply.github.com>
Desc: Merge pull request #20791 from mnjul/bug_1027536_lockscreen_clock_stall

Bug 1022984 / Bug 1027536 - After Restarting Phone, Lockscreen Time Always Shows as 5:32 or Is Stalled. r=gweng

========

https://hg.mozilla.org/integration/gaia-central/rev/131595e10f13
Author: John Lu [:mnjul] <jlu@mozilla.com>
Desc: Bug 1022984 / Bug 1027536 - After Restarting Phone, Lockscreen Time Always Shows as 5:32 or Is Stalled
Bumping manifests a=b2g-bump