m8: increase ui responsiveness

* lower touchslop, improves scroll response
* speed up the notification shade

Change-Id: I0262a5b359d4298a44bf8211baca13e01fa59536
Nuke Cam2 overlay to fix Camera preview freeze

Change-Id: I40f7911cff67f251493f8a51c08a3dd3feabdd20
Fix OmniTorch building
Bring in DeviceSettings

Change-Id: I0e3710d6d79a4478608cac9c1d0e75fad26ea36e

Conflicts:
	overlay/packages/apps/Settings/res/values/bools.xml