Add memory allocation statistics to the Bluetooth dumpsys output

The following memory allocation statistics are added to
the "dumpsys bluetooth_manager" output.
Those are tracking the allocations that are using the OSI malloc mechanism:
osi_strdup() / osi_strndup() / osi_malloc() / osi_calloc() / osi_free()

Bluetooth Memory Allocation Statistics:
  Total allocated/free/used counts : 4063 / 3323 / 740
  Total allocated/free/used octets : 922460 / 607941 / 314519

Test: Running "adb shell dumpsys bluetooth_manager"
Change-Id: Ibe1d28ec3a2acfd87cfaa10e5902ef3b596e64a8