Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/9a31ee47215f
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #24630 from julienw/1076169-fix-camera-tests

Bug 1076169 - [Camera] fix camera tests with a newer mocha (again) r=wil...

========

https://hg.mozilla.org/integration/gaia-central/rev/812eaecf52e2
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 1076169 - [Camera] fix camera tests with a newer mocha (again) r=wilsonpage

========

https://hg.mozilla.org/integration/gaia-central/rev/f379765506ae
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #24855 from davidflanagan/bug1072075

Bug 1072075: don't allow system time changes to affect app usage timings r=marshall

========

https://hg.mozilla.org/integration/gaia-central/rev/8e1e26d38a58
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Bug 1072075: don't allow system time changes to affect app usage timings
(cherry picked from commit 83af4279c67b36c96b04ffec04ae428b69eec51d)

reference bug 1069863 in comments

fix broken unit tests
Bumping manifests a=b2g-bump