Dynamic Sensor Discovery Implementation

Defined the dynamic sensor meta data type and UUID of sensor, as well
as the broadcast intent that is related to dynamic sensor status
change.

Modify SensorManager, SystemSensorManager and the JNI layer to support
dynamic sensor discovery.

Added SensorNotificationService to notify apps that sensor connected
or disconnected via broadcast.

Change-Id: I28adfb005357d7e3983d65117d6865830c75027d