(#10915) Fix tests to work with new parameter checking

The change to how the property checks if the provider can be called
caused several tests to fail because they were not using providers that
were able to properly report respond_to?. This fixes those tests. In
the case of the host_spec.rb I was able to convert away from a mock, but
in the mount_spec.rb the mock had to mock respond_to? since the
interaction with the provider seems to be more complicated than I can
unravel.