[Runtime] Create a component for SysApps

This class is the glue between the XWalkRunner and the
SysAppsManager. The sysapps/ directoy doesn't depend on runtime/, so the
glue code is used instead of making SysAppsManager implement
XWalkComponent.

By overriding the factory method the Android and Tizen can configure
which extensions they need to disable, instead of manually creating the
RawSockets extension.

In the case of Tizen, we create a component just for the currently used
implementation of DeviceCapabilities -- a newer one is being implemented
and will replace it when achieve feature parity.