Statsd: Enable host_supported for libstatslog

* libutils must be used as a static library when compiled on host
* Host does not have Android system properties and hence we cannot
  use <cutils/properties.h>. In fact, properties.cpp is not even
  compiled on host for libcutils. Therefore, this CL adds a check
  for __ANDROID__ macro before including <sys/propoerties.h> and
  before calling properties_get_bool()
* On host, statsd logging will be disabled since host does not
  use statsd for anything

Fixes: 121294178
Test: test drive statsd
Change-Id: I838ff02468c650c5f7d85e68fa5008b98f08ce8c