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

========

https://hg.mozilla.org/integration/gaia-central/rev/99e60837965b
Author: Jan Keromnes <janx@linux.com>
Desc: Merge pull request #18795 from staktrace/killsettings

Merge pull request #18795 from staktrace/killsettings. r=me

========

https://hg.mozilla.org/integration/gaia-central/rev/37a3326f4463
Author: Kartikaya Gupta <kgupta@mozilla.com>
Desc: Bug 1003228 - Remove redundant force-enabling of APZ in developer builds. r=janx

========

https://hg.mozilla.org/integration/gaia-central/rev/a0210ba68ce7
Author: Kartikaya Gupta <kgupta@mozilla.com>
Desc: Bug 1003228 - Remove the toggle button for APZ from the sleep menu. r=janx

========

https://hg.mozilla.org/integration/gaia-central/rev/2ec5b8166f5a
Author: Kartikaya Gupta <kgupta@mozilla.com>
Desc: Bug 1003228 - Remove some graphics options from the developer menu as they are not needed any more. r=janx
Bumping manifests a=b2g-bump