Initialize native Sensor object correctly

This CL gives default values for all fields in Sensor native
object.

Bug: 37640915
Test: added local logging to verify all native sensor objects are
      initialized correctly.

Change-Id: I4076756249788f56960c74629cb800f1b2bae79f
Merged-In: I4076756249788f56960c74629cb800f1b2bae79f