Fix net_test_bluetooth

* net_test_bluetooth should try to load Bluetooth library from
  system/lib/hw or system/lib64/hw if it cannot find it from default
  path
* Also replaced legacy logging macro with libbase logging statements

Bug: 67059247
Test: net_test_bluetooth
Change-Id: I6c45f66aedf675397f377ca56203bec9708324e1