Always throw a ConnectionException on error

There was a single case where we would return a 'null' for the service
connect; if bindServiceAsUser() returned 'false'. Handle this condition
with an exception. Also make the exception descriptive enough so we
can add the correct resolution status to the resolution logs.

Change-Id: I6cee25adfa74745579577cb9726f8dd9c2950746
Fixes: 38131147
Test: Manual; restart the resolver and see the exceptions