Add additional logging to track HAL connection.

We perform lazy initialization of sensors. This leads to a possibility
when dumsys would report "No Sensors" for both the cases of the HAL
returning no sensors and us never actually having queried the HAL.

Bug: 37904273
Test: Sensors stream, new text for device init check shows up in
      dumpsys.

Change-Id: I705eb302811538797f96ac878c23149a483189a5