Lockscreen Notifications: make dynamic width a device overlay setting

dynamic width is disabled by default, to enable it for a specific device, add
<bool name="config_lnDynamicWidth">true</bool>
to yourdevicetree/overlay/frameworks/base/packages/Keyguard/res/values/config.xml

Conflicts:
	packages/Keyguard/src/com/android/keyguard/NotificationHostView.java